JPWO2000069121A1 - Information processing method, information processing system, and information processing device - Google Patents

Abstract

(57) [Abstract] When transmitting information between a plurality of devices connected via a network, an information disclosure data storage unit is set to disclose specified information to the devices connected via the network, the information disclosure data storage unit is in a specified hierarchically structured descriptor format, the specified information is stored in a board 910 set in the descriptor format, the top-level descriptor 900 of the hierarchical structure directly indicates the storage location of the specified board 900, and information related to the specified information is stored in information areas 921, 922, 931, 932 indicated by tracing the hierarchical structure from the top-level descriptor 900.

Description

Detailed Description of the Invention

TECHNICAL FIELD The present invention relates to an information processing method, an information processing system, and an information processing device suitable for use in electronic devices such as AV devices that are connected to a network and remotely controlled. More specifically, the present invention relates to a case where information stored in devices is shared between devices using control commands such as so-called AV/C commands.
and Electronics Engineers) standardized IE
AV devices have been developed that can transmit information to each other via a network using an EE1394 serial data bus. In this network, a specific command (AV/C Command Transaction Sequence) is used.
It is possible to mutually control AV devices connected to the above network using the IEEE 1394 standard and AV/C commands. For details of the IEEE 1394 standard and AV/C commands, see 1394 Trade Association.
AV/C Digital Interface published by ciation
In FIG. 1, by using such an IEEE 1394 serial data bus 51 (hereinafter referred to as bus 51), for example, an IRD (Integrated Receiver Device) which is a digital satellite receiver that receives and decodes digital satellite broadcasts can be used.
The video received by the video decoder 52 is transmitted to a DVCR (Digital Video Camera) which is a video recording and playback device connected via a bus 51.
Furthermore, the IRD 52 and DVCR 53 can be used to perform so-called scheduled recording.
This is possible through control based on the C command. When performing scheduled recording with this device, the IRD 52 and DVCR 53 are controlled by a controller 54 provided within the IRD 52. In this case, the settings for scheduled recording (channel, start time, etc.) are made in the IRD 52.
When the set start time arrives, the controller 54 outputs a command to the digital tuner 55 in the IRD 52 to select the set channel.
Among the signals captured by the antenna 56, video signals and the like received by the digital tuner 85 are output to the bus 81. At the same time, a command to start recording is sent from the controller 54 via the bus 51 to the recorder 57 provided in the DVCR 53. In response, the recorder 57 extracts the video signals and the like selected and received by the digital tuner 55 from the bus 51 and records them on a recording medium such as magnetic tape. In this way, scheduled recording is performed. Furthermore, the DVCR 53 is also provided with a controller 58, which controls, for example, recording of video signals and the like received by the built-in analog tuner 59 by the recorder 57. In this way, when information within a device is shared with other devices using AV/C commands that remotely control network-connected devices, conventionally, a VOR subunit,
This has been done by setting up a list within the subunits that are the control targets, such as tuner subunits. However, with this method, the content of the information to be shared is limited to that related to each subunit. Furthermore, as network systems continue to develop in the future, there is a possibility that the content of the information to be shared will not only be specific to each subunit, but that there will be a demand to handle information of various types. In response to this, the inventor of this application has previously proposed the AV/C Bulletin Board subunit (AV/C Bulletin Board) as a space for sharing information that is independent of the subunit.
Letin Board Subunit (hereinafter referred to as BBS) was proposed (1394 Trade Association Board Subunit
(See General Specification, Rev. 0.38).
According to this, any information can be shared on the BBS, and mutual control can be exercised between any devices. However, in the BBSs proposed so far, the method of coexistence when multiple types of boards exist, and the list structure when multiple boards of the same type exist are unclear, and it has not been possible to efficiently store a variety of data. Therefore, when reading or writing data from other devices, it is necessary to read all the data on the BBS before processing, for example, which creates the problem of complicated processing, and there has been a demand for a system that allows for efficient writing and reading using the BBS. Disclosure of the Invention The present invention has been made in light of these points, and is a solution to the problems of conventional information processing methods,
The objective of this invention is to enable efficient information processing using a bulletin board system (BBS), which is not possible with an information processing system or information processing device. The first invention relates to an information processing method for transmitting information between multiple devices connected via a network, which includes: establishing an information disclosure data storage unit that discloses predetermined information to the devices connected via the network; configuring the information disclosure data storage unit in a predetermined hierarchically structured descriptor format; storing the predetermined information in a board set in the descriptor format; using the highest descriptor in the hierarchical structure to directly indicate the storage location of the predetermined board; and storing information related to the predetermined information in an information area indicated by tracing the hierarchical structure from the highest descriptor. This allows other devices connected via the network to easily determine the storage location of the predetermined information to be disclosed via the network, making it easy to read the information. The storage location of information related to the predetermined information can also be easily determined. A second invention is the information processing method of the first invention, wherein the information area is set to an area where information can be written from devices other than the device to which the descriptor is set, and an area where information writing from other devices is restricted. This allows for accurate protection of writing from other devices only for necessary information. A third invention is the information processing method of the second invention, wherein, when the area where information can be written is set, information regarding the writable capacity is added to the descriptor. This allows other devices to determine the amount of information that can be written, and information can be written efficiently within the provided area. A fourth invention is the information processing method of the first invention, wherein an ID is added to each piece of information stored on the specified board, and a common ID is also added to each piece of information stored in the information area, thereby enabling correspondence between the information stored on the board and the information area. This allows the correspondence between the information stored on the board and the information area to be easily determined simply by referencing the ID. The fifth invention is an information processing system for transmitting information between a plurality of devices connected via a network, wherein a first device connected to the network is provided with an information disclosure data storage unit that discloses specified information to devices connected via the network, and a control unit that reads or writes the data stored in the information disclosure data storage unit by receiving a specified command via the network, and a control unit that issues a command to a second device connected to the network instructing it to read or write data stored in the information disclosure data storage unit, data is stored in the information disclosure data storage unit provided in the first device in a specified hierarchically structured descriptor format, the specified information is stored in a board set in the descriptor format, the highest descriptor in the hierarchical structure directly indicates the storage location of the specified board, and information related to the specified information is stored in an information area indicated by tracing the hierarchical structure from the highest descriptor. In this way, the storage location of the predetermined information to be disclosed via the network can be easily determined from the second device connected via the network, and a system can be obtained in which the information can be easily read from the first device. Also, the storage location of information related to the predetermined information can be easily determined within the system. The sixth invention is an information processing system according to the fifth invention, wherein the information area in the information disclosure data storage unit of the first device contains:
An area into which information can be written from the second device and an area into which information writing from the second device is restricted are set. This allows for accurate protection of writing from the second device only for necessary information. A seventh invention is an information processing system according to the sixth invention, wherein, when an area into which information can be written is set as the information area, a storage area for information regarding the writable capacity is added to the descriptor, and the control unit of the second device determines the writable capacity. This allows the second device to determine the writable capacity of information, resulting in a system in which information can be written effectively within the provided area. An eighth invention is an information processing system according to the fifth invention, wherein an ID is added to each piece of information stored on a predetermined board in the information disclosure data storage unit of the first device, and a common ID is also added to each piece of information stored in the information area, and the control unit of the second device determines the correspondence between the information stored on the board and the information area based on the ID. By doing this, the correspondence between the information stored on the board and the information stored in the information area can be easily determined on the second device side by simply referencing the ID. A ninth invention is an information processing device that transmits information to other devices connected via a network, comprising: an information disclosure data storage unit that discloses predetermined information to the other devices connected via the network; and a control unit that reads or writes the data stored in the information disclosure data storage unit by receiving a predetermined command via the network. Data is stored in the information disclosure data storage unit in a predetermined hierarchically structured descriptor format; the predetermined information is stored in a board set in the descriptor format; the highest descriptor in the hierarchical structure directly indicates the storage location of the predetermined board; and information related to the predetermined information is stored in an information area indicated by tracing the hierarchical structure from the highest descriptor. This configuration allows the storage location of the predetermined information to be disclosed via the network to be easily determined by other devices connected via the network, making it easy to read the information. In addition, the storage location of information related to the specified information can be easily determined by other devices communicating with this device. A tenth aspect of the invention is the information processing device of the ninth aspect, wherein the information area in the information disclosure data storage unit is configured to include an area where information can be written from other devices and an area where information writing from other devices is restricted. This allows for accurate protection of writing from other devices connected via a network only for necessary information. A eleventh aspect of the invention is the information processing device of the tenth aspect, wherein when an area where information can be written is set as the information area, a storage area for information regarding the writable capacity is added to the descriptor. This allows other devices connected via the network to determine the capacity of information that can be written, allowing information to be written efficiently within the provided area. A twelfth aspect of the invention is the information processing device of the ninth aspect, wherein an ID is added to each piece of information stored in a specified board in the information disclosure data storage unit, and a common ID is also added to each piece of information stored in the information area. By doing so, the correspondence between the information stored on the board and the information area can be easily determined by simply referring to the ID on the side of other devices connected via a network. BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to Figures 2 to 32. First, an example of the overall configuration of the audio/video system of this example will be described with reference to Figure 2. That is, as shown in Figure 2, for example, a bus line 1 specified by IEEE 1394 is connected to an IRD 100, which is a digital satellite receiver that receives and decodes digital satellite broadcasts, and a DVCR 20, which is a digital video recording/playback device.
0 are connected to the bus line 1. Other devices (not shown) may be connected to the bus line 1. The DVCR 200 has a BBS (Bulletin Board System) that functions as a bulletin board for disclosing information to other devices.
The BBS 4 is provided with a bulletin board subunit (BBS) 4.
The setting is made by storing the relevant data in a partial area of the memory connected to the controller 10 in the DVCR 200. The stored data of this BBS4 can be read and written by the controller 10 in the DVCR 200.
The IRD 100 is provided with a BBS controller 5 that reads and writes the BBS on the DVCR 200 side. The IRD 100 uses, for example, an AV/C descriptor mechanism defined by AV/C commands to control reading and writing. The AV/C commands will be described in detail later. When performing scheduled recording, the IRD 100 and the DVCR 200 are controlled by the BBS controller 5 of the IRD 100. The settings for scheduled recording (channel, start time, end time, etc.) are then made by the controller 6 of the IRD 100.
When the set start time arrives, the BBS controller 5 outputs a command to the digital tuner 7 to select the set channel, and transmits the video signal etc. selected and received by the digital tuner 7 from the signals picked up by the antenna 8 to the bus 1.
At the same time, the BBS controller 5 outputs the BB signal to the DVCR 200 via the bus 1.
A recording start command is sent to S4. This causes the BBS 4 of the DVCR 200 to output a command to the recorder 9, which extracts the video signal, etc., selected and received by the digital tuner 7 from the bus 1 and records it on a recording medium such as a magnetic tape. In this way, scheduled recording is performed.
A controller 10 is also provided for the BBS controller 5, which controls the recording of video signals received by a built-in analog tuner 11 by a recorder 9. Although the BBS controller 5 and the controller 6 are shown as separate entities in FIG.
In practice, for example, a part of the CPU constituting the controller 6 is set to function as the BBS controller 5. Figure 3 shows the configuration of the IRD 100. Broadcast radio waves from a satellite are received by the antenna 8, input to the terminal 100a, and supplied to a tuner 101, which serves as a program selection means provided in the IRD 100. The IRD 100 is configured so that each circuit operates under the control of a central control unit (CPU) 111, and the tuner 101 obtains a signal of a predetermined channel. The received signal obtained by the tuner 101 is supplied to a descrambling circuit 102. The descrambling circuit 102 decodes the signal using an IC card (
Based on the encryption key information of the contracted channel stored in the MPEG decoder 104 (not shown), only the multiplexed data of the contracted channel (or an unencrypted channel) is extracted from the received data and supplied to a demultiplexer 103. The demultiplexer 103 rearranges the supplied multiplexed data for each channel, extracts only the channel designated by the user, and sends a video stream consisting of packets of the video portion to an MPEG video decoder 104, and also sends an overlap stream consisting of packets of the audio portion to an MPEG audio decoder 109. The MPEG video decoder 104 decodes the video stream to restore the video data before compression encoding, and outputs this to an NTSC audio decoder 109 via an adder 105.
The NTSC encoder 106 converts the video data into an NTSC
The IRD 100 converts the NTSC data into a luminance signal and color difference signals in the NTSC format, and sends them to a digital-to-analog converter 107 as NTSC format video data. The digital-to-analog converter 107 converts the NTSC data into an analog video signal, and supplies this to a connected television receiver (not shown). The IRD 100 of this example also includes a GUI data generator 108 that generates various display video data for a graphical user interface (GUI) under the control of the CPU 111. The GUI video data (display data) generated by the GUI data generator 108 is supplied to an adder 105, where it is converted into an MPE
The GUI image is superimposed on the video data output by the G video decoder 104 so that it is superimposed on the received broadcast video. The MPEG audio decoder 109 decodes the audio stream to restore the PCM audio data before compression encoding and sends it to the digital/analog converter 110. The digital/analog converter 110 converts the PCM audio data into analog signals to generate LCh audio signals and RCh audio signals.
The IRD 100 of this example outputs the video stream and audio stream extracted by the demultiplexer 103 as sound through the IEEE1394 interface unit 112.
and then transmits it to the IEEE1394 bus line 1 connected to the interface unit 112. The received video stream and audio stream are transmitted in isochronous transfer mode.
When the data generating unit 108 is generating image data for GUI, the image data is supplied to the interface unit 112 via the CPU 111, and the interface unit 112 transmits the image data for GUI to the bus line 1. The CPU 111 is connected to a work RAM 113 and a RAM 114, and control processing is performed using these memories. In addition, operation commands from an operation panel 115 and remote control signals from an infrared receiving unit 116 are input to the CPU 111.
1, and can perform operations based on various operations.
The CPU 111 is configured to be able to determine commands and responses transmitted from the bus line 1 to the interface unit 112. Fig. 4 is a block diagram showing an example of the configuration of the DVCR 200. The recording system is configured to receive digital broadcast data from a predetermined channel using a tuner 201 built in the DVCR 200 and convert the received data into MPEG (Moving Picture Experts Group) format data.
The data is supplied to a Picture Experts Group (MPEG) encoder 202, which converts the data into video and audio data in a format suitable for recording, such as MPEG2 format. If the received broadcast data is in MPEG2 format, no processing is performed by the encoder 202. The data encoded by the MPEG encoder 202 is supplied to a recording/playback unit 203, where it is processed for recording, and the processed recording data is then sent to a rotary head drum 20.
The analog video and audio signals are supplied to the recording head in the tape cassette 204 and recorded on the magnetic tape in the tape cassette 205. The analog video and audio signals input from the outside are converted into digital data by the analog/digital converter 206, and then output to the MPEG encoder 202.
The data is converted into, for example, MPEG2 video data and audio data, and is supplied to the recording/playback unit 203 where it is processed for recording. The processed recording data is then fed to the rotary head drum 20.
The signal is supplied to the recording head in the tape cassette 204 and recorded on the magnetic tape in the tape cassette 205. The playback system is configured such that the signal obtained by playing back the magnetic tape in the tape cassette 205 with the rotary head drum 204 is played back in the recording/playback unit 203 to obtain video data and audio data. This video data and audio data are then fed to the MPEG decoder 204.
07, where it is decoded from, for example, the MPEG2 format. The decoded data is supplied to a digital/analog converter 208, where it is converted into analog video and audio signals, and output to the outside. The DVCR 200 also has an interface unit 209 for connecting to an IEEE 1394 bus, so that the video and audio data obtained by this interface unit 209 from the IEEE 1394 bus side can be supplied to the recording/playback unit 203, where it can be recorded on the magnetic tape in the tape cassette 205. The video and audio data played back from the magnetic tape in the tape cassette 205 can be supplied from the recording/playback unit 203 to the interface unit 209, where it can be sent to the IEEE 1394 bus side. During transmission via this interface unit 209, the DVCR 200 can select a format for recording on a medium (magnetic tape) (for example, the above-mentioned MPEG2 format) and a format for recording on a medium (magnetic tape) (for example, the above-mentioned MPEG2 format).
When the data format transmitted on the E1394 bus is different from that of the DVCR2,
The format conversion may be performed by a circuit within the DVCR 200. Recording and playback processes in the DVCR 200 and transmission processes via the interface section 209 are executed under the control of a central control unit (CPU) 210. The CPU 210 is connected to a memory 211 which is a work RAM.
Operation information from an operation panel 212 and control information from a remote control device received by an infrared receiving section 213 are supplied to the CPU 210, and operation control corresponding to the operation information and control information is carried out.
When the interface unit 209 receives control data such as AV/C commands (described later) via the H.394 bus, the data is supplied to the CPU 210.
The CPU 210 is adapted to perform corresponding operational control. Next, a process of data transmission on the IEEE 1394 bus 1 connecting the devices 100 and 200 will be described. Fig. 5 shows the cycle structure of data transmission between devices connected by IEEE 1394. In IEEE 1394, data is divided into packets and stored in 125µm packets.
The isochronous packet is transmitted in a time-division manner based on a cycle of length S. This cycle is generated by a cycle start signal supplied from a node with cycle master functionality (any device connected to the bus).
The bandwidth required for transmission (measured in time units, but called bandwidth) is secured from the beginning of every cycle. Therefore, isochronous transmission guarantees data transmission within a certain period of time. However, if a transmission error occurs, there is no mechanism to protect against it.
Data will be lost. In asynchronous transmission, the node that secures the bus as a result of arbitration sends an asynchronous packet during the time not being used for isochronous transmission in each cycle. Reliable transmission is guaranteed by using acknowledgements and retries, but the timing of transmission is not constant. In order for a specific node to perform isochronous transmission, that node must support the isochronous function. Furthermore, at least one node that supports the isochronous function must have cycle master functionality. Furthermore, at least one node connected to the IEEE 1394 serial bus must have isochronous resource manager functionality. IEEE 1394 uses a CSR (Control & Status Register) with a 64-bit address space specified in ISO/IEC 13213.
) architecture. Figure 6 is a diagram explaining the structure of the address space of the CSR architecture. The upper 16 bits are a node ID that identifies each node on the IEEE 1394, and the remaining 48 bits are used to specify the address space assigned to each node. These upper 16 bits are further divided into 10 bits for the bus ID and 6 bits for the physical ID (node ID in the narrow sense). Values with all bits set to 1 are used for special purposes, so 1023 buses and 63 nodes can be specified. The space specified by the upper 20 bits of the 256 terabyte address space specified by the lower 48 bits is used for 2048 bytes of CSR-specific registers and IE
Initialization register space (Init) used for EE1394 specific registers etc.
Real Register Space, Private Space (Priva
Initial Memory Space), and Initial Memory Space
The space defined by the lower 28 bits is used as a configuration ROM (Configuration Read Only ROM) when the space defined by the upper 20 bits is used as an initialization register space.
memory), initialization unit space (In
Initial Unit Space, Plug Control Register (Plug
The CSRs are used as control registers (PCRs). Figure 7 shows the offset addresses, names, and functions of the main CSRs. The offset in Figure 7 is FFFFF0, where the initialization register space begins.
This indicates the offset address from the address 000000h (the number with an "h" at the end indicates that it is a hexadecimal representation).
The Bandwidth Available Register (BAV) indicates the bandwidth that can be allocated to isochronous communication, and only the value of the node operating as an isochronous resource manager is valid. That is, each node has the CSR in FIG. 6, but only the Bandwidth Available Register of the isochronous resource manager is valid. In other words, the Bandwidth Available Register is essentially only owned by the isochronous resource manager. The Bandwidth Available Register stores the maximum value when no bandwidth is allocated to isochronous communication, and the value decreases each time a bandwidth is allocated. The Channel Available Register (CHA) at offsets 224h to 228h stores the maximum value when no bandwidth is allocated to isochronous communication.
Each bit of the Channels Available Register corresponds to a channel number from 0 to 63, and if the bit is 0, it indicates that the channel has already been assigned. Only the Channel Available Register of a node operating as an isochronous resource manager is valid. Returning to FIG. 6, the following registers are stored at addresses 200h to 400h in the initialization register space:
A configuration ROM based on the general ROM (read only memory) format is arranged.
The bus info block, root directory, and unit directory are arranged. Company ID in the bus info block
The ID number indicating the manufacturer of the device is stored in the chip ID field.
) stores a unique ID specific to the device, which is not duplicated with other devices. In order to control the input/output of the device via the interface, the node stores the IEC188
3, which embodies the concept of a plug in order to form a signal path that is logically similar to an analog interface. FIG. 8 is a diagram explaining the configuration of the PCR. The PCR is an oPCR (output Plug Control Register) that represents an output plug.
g Control Register), iPCR representing the input plug (inp
It also has a PCR Plug Control Register.
is a register oMPR(
output Master Plug Register) and iMPR (in
Each device has a Master Plug Register.
Although there are no multiple MPRs and iMPRs, it is possible to have multiple oPCRs and iPCRs corresponding to individual plugs depending on the capabilities of the device.
The PCRs shown in FIG. 8 each have 31 oPCRs and iPCRs.
The flow of isochronous data is controlled by manipulating the registers corresponding to these plugs. Figure 9 shows the configuration of the oMPR, oPCR, iMPR, and iPCR. Figure 9A shows the configuration of the oMPR, Figure 9B shows the configuration of the oPCR, and Figure 9C shows the configuration of the iMPR.
9D shows the configuration of oMPR and iMPR, respectively.
The data rate capability of the 2 bits on the MSB side of
The oMPR broadcast channel base (br) stores a code indicating the maximum transmission rate of isochronous data that the device can transmit or receive.
The broadcast channel base specifies the number of the channel used for broadcast output. The number of output plugs (number of output plugs) in the 5 least significant bits of the oMPR.
The number of output plugs (oPCR) indicates the number of output plugs that the device has.
The value indicating the number of input plugs (n
The number of input plugs in the device, i.e., a value indicating the number of iPCRs, is stored in the "number of input plugs." The main extension field and auxiliary extension field are areas defined for future extensions. The online (on-line) MSB of the oPCR and iPCR indicates the usage status of the plug. That is, if the value is 1, the plug is online, and if it is 0, it is offline. The broadcast connection counters of the oPCR and iPCR
The value of oPC indicates whether a broadcast connection exists (1) or not (0).
R and iPCR are 6-bit wide point-to-point connection counters.
The value of the point-to-point connection (po
It represents the number of int-to-point connections. A point-to-point connection (so-called p-to-p connection) is a connection for transmitting only between one specific node and another specific node. The number of channels (channels) with a 6-bit width of oPCR and iPCR.
The value of the oPCR data rate (data rate number) indicates the number of the isochronous channel to which the plug is connected.
The value of oPCR) indicates the actual transmission speed of the isochronous data packet output from the plug.
The code stored in the overhead ID indicates the bandwidth of the isochronous communication.
The value of d) represents the maximum value of data contained in an isochronous packet that the plug can handle. Figure 10 shows the relationship between plugs, plug control registers, and isochronous channels. Here, the devices connected to the IEEE 1394 bus are shown as AV devices 71 to 73.
oPCR in which the transmission rate and the number of oPCRs are specified by the oMPR of the V device 73

Among oPCR[0] to oPCR[2], the isochronous data whose channel is specified by oPCR[1] is transmitted to channel #1 (c
The iPCR in which the transmission rate and the number of iPCRs are specified by the iMPR of the AV device 71 is sent.

Of [0] and iPCR[1], input channel #1 has the transmission rate and iPCR

[0] allows the AV device 71 to
The AV device 72 reads the isochronous data sent to channel #1 of the E1394 serial bus.

The AV device 71 sends isochronous data to channel #2 specified by iPRC [0], and the AV device 71 reads the isochronous data from channel #2 specified by iPRC [1]. In this way, data is transmitted between devices connected by the IEEE 1394 serial bus. In the system of this example, the AV/C command set, which is defined as commands for controlling devices connected via the IEEE 1394 serial bus, is used to control each device and determine its status. Next, this AV/C command set will be explained. First, the subunit identifier descriptor in the AV/C command set used in the system of this example will be explained.
The data structure of a subunit identifier descriptor (Sub-Unit Identifier Descriptor) will be described with reference to Figs. 11 to 14. Fig. 11 shows the data structure of a subunit identifier descriptor. As shown in Fig. 11, a list is formed from a hierarchical list of subunit identifier descriptors. A list represents, for example, the channels that can be received in the case of a tuner, or the songs recorded on a disc in the case of a disc. The list at the top of the hierarchical structure is called a root list, and for example, list 0 is the root for the lists below it.
Other lists are also root lists in the same way. There are as many root lists as there are objects. Here, an object is, for example, each channel in a digital broadcast when the AV device connected to the bus is a tuner.
All lists in a hierarchy share common information. Figure 12 shows the general subunit descriptor.
The subunit descriptor contains attribute information about the function. Descriptor length (descriptor)
The length field does not include a value of the field itself. The generation ID indicates the version of the AV/C command set, and its value is, for example, "00h" (h represents hexadecimal).
Here, "00h" indicates that the data structure and commands are in accordance with the AV/C General Specification, as shown in FIG.
This means that the version is 3.0 of the RFC 2000 standard. As shown in Figure 13, all values except "00h" are reserved for future specifications. The list ID size indicates the number of bytes in the list ID. The object ID size indicates the number of bytes in the object ID.
Object ID indicates the number of bytes of the object ID. Object position size indicates the position (number of bytes) in the list used for reference during control. Number of root object lists
indicates the number of root object lists.
D (root object list id) indicates an ID for identifying the root object list at the top of each independent hierarchy.
The ngth is the data field belonging to the following subunit (subunit
The data field belonging to the subunit indicates the information specific to the function.
The pendent length is the length of the subsequent manufacturer specific data.
This field indicates the number of bytes in the "factory dependent information" field. The manufacturer specific data is a field that indicates the specification information of the vendor (manufacturer). If there is no manufacturer specific data in the descriptor, this field does not exist. Figure 14 shows the allocation range of the list ID shown in Figure 12. As shown in Figure 14, "0000h to 0FFFh" and "4000h to FFFFh" are assigned.
" is reserved as an allocation range for future specifications.
The "h to 3FFFh" and "10000h to maximum value of list ID" are provided to identify the subordinate information of the function type. Next, the AV/C command set used in the system of this example is shown in FIG.
15 shows a stack model of the AV/C command set. As shown in FIG. 15, there are a physical layer 81, a link layer 82, and a
2, the transaction layer 83, and the serial bus management 84
Compliant with EEE1394. FCP (Function Control Protocol)
The AV/C Command Set 86 conforms to the 1394TA specification. Fig. 16 is a diagram for explaining the commands and responses of the FCP 85 in Fig. 15. FCP is a protocol for controlling devices (nodes) on an IEEE 1394 bus. As shown in Fig. 16, the controlling side is the controller, and the controlled side is the target. The transmission of an FCP command or response is as follows:
This is done between nodes using a write transaction of IEEE 1394 asynchronous communication. The target that receives the data returns an acknowledgement to the controller to confirm receipt. Figure 17 is a diagram for explaining in more detail the relationship between the FCP commands and responses shown in Figure 16. Node A and node B communicate via the IEEE 1394 bus.
are connected. Node A is the controller and node B is the target.
Both node A and node B are provided with a command register and a response register of 512 bytes each. As shown in Fig. 17, the controller transmits an instruction by writing a command message to the command register 93 of the target. Conversely, the target transmits an instruction by writing a command message to the response register 92 of the controller.
A response is conveyed by writing a response message to the FCP. Control information is exchanged in response to the above two messages. The type of command set sent by FCP is written in the CTS in the data field in Figure 18, which will be described later. Figure 18 shows the data structure of a packet transmitted in the asynchronous transfer mode of an AV/C command. The AV/C command set is a command set for controlling AV equipment, and CTS (command set ID) = "0000". AV/C command frames and response frames are exchanged between nodes using the above FCP. In order to avoid placing a burden on the bus and AV equipment, responses to commands are to be made within 100 ms. Figure 18
As shown in the figure, the data of the asynchronous packet is 32 bits in the horizontal direction (=1
The upper part of the figure shows the header part of the packet, and the lower part shows the data block.
CTS indicates the ID of the command set, and in the AV/C command set,
TS="0000". C type/response
The field of (se) indicates the function classification of the command if the packet is a command, and indicates the processing result of the command if the packet is a response. Commands are broadly divided into (1) commands that externally control functions (CONTROL), (2) commands that externally inquire about the status (STATUS), and (3) commands that externally inquire about the support of control commands (GENERAL INQUIRY).
Y (opcode support or not) and SPECIFIC INQUIRY
(4) A command (NOTIFY) that requests that a change in status be notified to the outside. A response is returned according to the type of command.
The response to the command is "Not Implemented" (NOT IMP
"LEMENTED", "ACCEPTED", "REJ"
There are two statuses: "STATUS" (STATE STATUS), "STATUS STATUS" (STATE STATUS), and "INTERIM" (STATE STATUS).
The response to the TUS command is "Not Implemented" (NOT IMPLEMENTED).
"MPLEMENTED", "REJECTED", "IN TRANSITION"
There are two commands: GENERAL INQUIRY, which is used to externally inquire about the support of a command.
Responses to the 'INQUIRY' and 'SPECIFIC INQUIRY' include 'IMPLEMENTED' and 'NOT IMPLEMENTED'.
The response to a command (NOTIFY) that requests notification of a change in state to the outside world is "Not implemented."
The subunit types are provided to specify the function within the device, for example, a tape recorder/player.
In addition to the functions corresponding to the device, this subunit type is also assigned to a BBS (Bulletin Board subunit), which is a subunit that publishes information to other devices. In order to distinguish between multiple subunits of the same type, addressing is performed using a subunit ID as a discrimination number. The opcode indicates the command, and the operand (
The operand represents the parameter of the command. Additional fields (additional operands) are also provided. 0 data or other data is added after the operand as needed. Data CRC (C
Cyclic Redundancy Check is used to check for errors during data transmission. Figure 19 shows a specific example of an AV/C command. The left side of Figure 19 shows a specific example of a c-type response. The upper part of the figure shows the command, and the lower part shows the response. "0000" indicates the control (CONTROL
L), "0001" for status, "0010" for specific inquiry, "0011" for notify, and "0100" for general inquiry.
GENERAL INQUIRY) is assigned.
"11" is reserved for future specifications. "1000" indicates not implemented (NOT IMPLEMENTED), and "1001" indicates acceptance (ACCEPTED).
"1010" indicates "REJECTED", "1011" indicates "IN TRANSITION", and "1100" indicates "IMPLANT".
STATE CHANGED (1101)
, "1111" is assigned to the provisional response (INTERIM).
10" is reserved for future specifications. The center of FIG. 19 shows an example of a subunit type: "00000"
"00011" is a disc recorder/player, "001
"00" is a tape recorder/player, "00101" is a tuner, and "001
"11" indicates a video camera, "01010" indicates a BBS, "11100" indicates a subunit type (Vender Unique) specific to a manufacturer, and "1111
0" contains a specific subunit type (Subunit type extend
ed tonext byte) is assigned to each subunit. Note that "11111" is assigned a unit, which is used when sending to the device itself, such as turning the power on and off. The right side of Fig. 19 shows a specific example of an opcode (operation code). There is an opcode table for each subunit type, and here, the opcode for the subunit type tape recorder/player is shown. Also, an operand is defined for each opcode. Here, "
"00h" contains a value specific to the manufacturer (Vender dependent), "5
"0h" is search mode, "51h" is time code, "52h" is ATN
, "60h" is assigned to open memory, "61h" to read memory, "62h" to write memory, "C1h" to load, "C2h" to record, "C3h" to play, and "C4h" to rewind. Fig. 20 shows specific examples of AV/C commands and responses. For example, when issuing a play command to a playback device as a target (consumer), the controller sends a command such as that shown in Fig. 20A to the target. This command is assigned to the AV/C
Since the command set is used, CTS is set to "0000".
Since the command (CONTROL) for controlling the device from outside is used in the type, c type="0000" is set (see FIG. 19). Since the subunit type is a tape recorder/player, subunit type="00100" is set.
" (See FIG. 19). The id indicates the case of ID0, and id=00
The operation code is "C3b" which means playback (see Figure 19).
See Figure 19). The operand is "75h", which means forward. Then, when playback is complete, the target returns a response like that shown in Figure 20B to the controller. In this case, "accepted" is included in the response, so the response is "1001" (see Figure 19). Except for the response, the rest is the same as Figure 20A, so a description will be omitted. Next, the structure of the BBS (Bulletin Board Subunit), which is a subunit prepared in the AV/C command set described above that publishes information to other devices, and the processing using this BBS will be described with reference to Figures 21 and onwards. In this example, the BBS is made up of hierarchically structured descriptors, for example as shown in Figure 21. That is, the BBS, which shows the data structure (list) of the BBS,
ID (Bulletin Board Subunit Identifier)
Descriptor) 900 is provided at the top level, and its BBSID
The root list ID indicated by 900 indicates the actual location of each descriptor and board. This BBSID is based on the Bulletin Board standard [1394
Trade Association Board Subunit Gene
This is a list defined in the BBS ID 900 [BBS ID 900] and is a list that every subunit of a bulletin board must have. The controller is supposed to read this list when it first accesses the BBS. Below this BBSID 900 are placed board lists and information lists. Two types of board lists and information lists are set: read-only and writable. That is, as shown in Figure 28, a list type value of 80 indicates a read-only board list, and a list type value of 81 indicates a writable board list. A list type value of 82 indicates a read-only information list, and a list type value of 83 indicates a writable information list. The read-only list here refers to a B
This is a list that cannot be written to by instructions from a controller of an external device other than the device that has the BBS, but can be written to by instructions from a controller inside the device that has the BBS. BBSID 900 contains basic information for reading and writing lists within a BBS. Specifically, as shown in Figure 22, predetermined information such as size is provided at the beginning of the list in BBSID 900. Following this information is a root list ID. Each root list ID is unique to each BBS.
The route list IDs are pointers to the board lists directly linked to the boards. A value is assigned to each of these route list IDs for each board type. That is, the route list IDs are determined by hexadecimal values ranging from 0000 to FFFF, as shown in the list ID assignment 901 in FIG. 22, for example.
Of these, 1000 to 1FFF are defined as route list IDs. Route list IDs 2000 to 3FFF are free space for default lists. Route list IDs 0000 to 1FFF and 4FF are free space for default lists.
F through FFFF are undefined. The values of these route list IDs are published in standards documents and the like. The above-mentioned BBSID 900 has a plurality of such route list IDs for each board type. In the example of FIG. 22, three types of BBSs, types A through C, are provided. Furthermore, after these route list IDs, the BBS
In this example, the route list ID of type A is the resource schedule board (R
SB) 910. Information relating to specific settings for scheduled recording (channel, start time, etc.) is written to this resource schedule board 910. An object ID is set for each piece of information written to the resource schedule board 910, and the information for that object ID is written to the resource schedule board 910. This object ID is commonly used as long as it is information relating to the same scheduled recording. That is, in this example,
Only basic information related to scheduled recording is written in the resource schedule board 910, and information list descriptors 921 and 922 (described later) are written.
, 931, 932 are written with information associated with each scheduled recording, and each item in the information list descriptor is written with the resource schedule board 9
The same object IDs as the object IDs of the items in 10 are set so that they correspond to each other. Then, the board list descriptors 920 and 930 shown in FIG. 22 are searched for by the root list IDs of types B and C of BBSID 900. Here, board list descriptor 920 is writable (Write E
This indicates a writable board list descriptor.
This indicates that writing is possible from the other device connected via bus line 1. Of course, writing is also possible from the controller in the device itself. The board list descriptor 920 first indicates the data length of the list, and then indicates that the board is writable as the list type. Furthermore, it indicates whether or not an object ID is present as an attribute, and the capacity of the board that can be formed as list information. It also indicates the number of prepared board entries. After this, information about each board is provided. That is, for example, if there are n board entries, there are board entries of 0 entry type to n-1 entry type, and the 0 entry type information 920a is as follows:
The entry type is indicated as a board, and an attribute indicates whether or not a child list is present. If a child list is present, a child list ID is provided. This child list ID indicates the position of a descriptor (#B-1) 921 as a child list. Furthermore, a field is provided in which information about the board type and details of the board type is written as entry information. Furthermore, the same number of such lists are provided as the number of boards. For example, one entry type information 920b is similarly provided, and the child list ID within that information indicates the position of a descriptor (#B-n) 922. Furthermore, the board list descriptor 930 shown in FIG. 22 indicates a read-only board list descriptor, and in this case, the list type is initially indicated as a read-only board. Here, read-only means that writing is not permitted by the other device connected via bus line 1. Writing is permitted by the controller within the device itself. Furthermore, an attribute indicates whether or not an object ID is present, and list information indicates the capacity of the board that can be formed and the number of board entries. This is followed by information about each board. For example, the entry type information 930a indicates that the entry type is a board, and whether or not the entry has a child list as an attribute. If the entry has a child list, a child list ID is provided.
The position of the descriptor 931 as a child list is indicated by the information list descriptor (#B-1) 931. Also, a field is provided in which information about the board type and details of the board type is written as entry information. Furthermore, as many such lists as there are boards, the information list descriptor (#B-1) 931 shown in FIG.
In 21, for example, first, the list type indicates that it is a writable information list. Furthermore, attributes indicate whether or not it has an object ID, and information on the capacity that can be formed as a list specific and the number of entries. This is followed by information on each piece of information. That is, 0-entry type information 921a indicates, for example, that it is preset information, and whether or not it has a child list as an attribute. If it does not have a child list, a child list ID field is not provided. Then, an object ID and, for example, preset information are provided. Furthermore, such lists are provided for the number of pieces of information.
Also, another information list descriptor (#B-n) at the same level
922 has a similar data structure, but details are omitted. The position of the information list descriptor (#C-1) 931, which is a child list of the board list descriptor 930, is indicated by the child list ID of the board list descriptor 930. Here, this information list descriptor #C-1 is the case where this descriptor also has a child list ID. The information list descriptor (#C-1) 931, for example, first indicates that the list type is read-only information. Attributes also indicate whether or not an object ID is present, list information, the capacity that can be formed as a list, and the number of entries. This is followed by information 931a regarding each piece of information. That is, the entry type indicates that the information is △△ information, and attributes indicate whether or not a child list is present. If a child list is present, a child list ID, an object ID, and an information entry are provided. Furthermore, as many such lists as the number of pieces of information are provided. The child list ID in this descriptor then searches for the information child list descriptor (#C-1-1) 932, which is a descriptor below that descriptor. This descriptor (#C-1-1) 932, for example, first indicates that the list type is a read-only board and whether or not it has an object ID as an attribute. It also indicates list information, the capacity that can be formed as a board, and the number of entries. Information about each piece of information, for example, 0-entry type information 932a, indicates whether or not it has a child list as an attribute. Information entry specifics are also provided. As many such lists as there are entries are provided. With a bulletin board subunit configured in this way, since a root list ID is assigned to each board type as described above, the controller can read the root list ID in the BBSID and compare it with the desired board type to determine whether the desired board type exists in the target subunit. Each root list ID indicates the first list that makes up the board, or a board list that groups together multiple boards of the same type. The configuration of a board and a board list is as follows: A board is made up of one or more information list descriptors. Furthermore, a board list descriptor that compiles multiple boards of the same type indicates a pointer to the information list descriptor at the beginning of each board. There are two types of board list descriptors that compile multiple board types: writable and read-only. These types can be identified by the list type. A writable board list allows the controller to remotely generate boards of the same type. When the controller detects that the list type is writable, it issues a command to execute a write, causing the data to be written, thereby setting the required data in the descriptor. Furthermore, to access this data, for example, the AV/C open/read/write descriptor (OPEN/READ/WRITE) specified by the AV/C command can be used.
This can be done using the OPEN DESCRIPTOR command. That is, when accessing a descriptor in a BBS, first send an OPEN DESCRIPTOR command with the configuration shown in Figure 29 to set the relevant descriptor to a state where it can be read or written.
In the command of this open descriptor, for example, as shown in FIG. 29, a value corresponding to the command of the open descriptor is placed in the column of the operation code, and the operand is

The value of the type of descriptor to be opened is placed in the [0] column, the value of the list ID to be opened is placed in the operand [1] and [2] columns, and the value of the subfunction is placed in the operand [3] column. For example, if opening for writing is desired, the value of write open is placed as the subfunction.
When opening for reading, a read open value is placed in the operand [4] and subsequent fields are left undefined. When reading data from a descriptor that has become accessible with the open descriptor command shown in Figure 29, a read command is sent to read the required data. Figure 30 shows the structure of this read command. To explain the structure, a value corresponding to the read descriptor command is placed in the opcode field, and a value corresponding to the operand [5] is placed in the operand [6].

Data for specifying the descriptor is placed in the fields from [0] onwards, and the type of data to be read from a specific operand, the data length, address, etc. are placed therein. When writing data to a descriptor that has become accessible by the open descriptor command shown in Figure 29, a write command is sent to write the required data. Figure 31 shows the structure of this write command. To explain the structure, a value corresponding to the write descriptor command is placed in the opcode field, and a value corresponding to the operand is placed in the operand field.

Data for specifying the descriptor is placed in the [0] column, and the following operands are placed with a subfunction, a group tag, a write data length, an address, the original data length before being rewritten, and the data to be written. The subfunction may be, for example, a subfunction that instructs partial rewriting. After reading with the read command shown in FIG. 30 or writing with the write command shown in FIG. 31, when access to the corresponding descriptor is to be terminated, a close command is executed to terminate the access. The close command uses a command with the same configuration as the open command, and is designed to instruct closing by a subfunction. That is, as shown in FIG. 32, a value corresponding to the open descriptor command is placed in the opcode column, and the operands are

The value of the type of descriptor to be opened is placed in the [0] column, the value of the list ID to be opened is placed in the operand [1] and [2] columns, and the value of the operand [
3] column, place the value of the subfunction that indicates the close.
Next, the process of reading the board indicated by BBSID 900 in FIG. 21 from the controller of another device on the bus line using an AV/C command is shown in FIG. 24.
This will be explained with reference to the flowchart in Figure 27. First, as shown in the flowchart in Figure 24, a command to read and open the SID (subunit identifier descriptor) of the BB subunit (Bulletin Board subunit) is sent to set it in a readable state (step S11). In this state, the SID of the BB subunit is specified, and the contents of that SID are read using a read descriptor command to find out the list ID size and the board type supported by the target BB subunit (step S12).
) Then, the SID of the BB subunit is closed (step S13). Next, an arbitrary list ID within the root list ID indicated by the SID is specified,
A read open command is sent to make the device ready for reading (step S14
Then, from the attribute data, it is determined whether the object in the list has an ID (step S15). Furthermore, it is determined whether the list type is writable (step S16). If it is writable, it detects the restrictions on entry writing (
Step S17). Then, when it is determined in step S16 that writing is not possible, or after detecting a restriction on entry writing in step S17, it is determined whether the list type is a board list (step S18). If it is determined in step S18 that it is a board list, the process moves to the flowchart of Figure 25, which is a process for reading out that board list entry. Here, the total number of entries in the relevant descriptor is detected from the data on the number of object entries in the relevant board list entry, and a counter set in the controller is initialized (step S21). Then, it is determined whether the total number of entries is greater than the count value of the counter (
Step S22). In the initial state, the total number of entries is greater than the count value of the counter. If the total number of entries is greater than the count value of the counter, it is determined whether the child list ID of the attribute in the object is 1 (i.e., whether a child list exists) (Step S23). Here, if the child list ID is 1,
If so, the child list ID is read (step S24). If it is determined in step S23 that there is no child list, or after the child list ID is read in step S24, the information information of the entry (entry specific information) is read (step S25).
The counter value is counted up (step S26), and the process returns to the determination in step S22. If the determination in step S22 is that the total number of entries is equal to the counter count value, a command to close this board list is sent, and reading is terminated (step S27). Also, if it is determined in step S18 of the flowchart in Figure 24 that it is not a board list (i.e., it is determined that it is an information list), the process moves to the flowchart in Figure 26, which is a process for reading information list entries. Here, the total number of entries in the corresponding descriptor is detected from the data on the number of object entries in the corresponding information list entry, and a counter set in the controller is initialized (step S31). Then, it is determined whether the total number of entries is greater than the counter count value (
Step S32). In the initial state, the total number of entries is greater than the counter count value. If this determination determines that the total number of entries is greater, the object ID is read (step S33). Furthermore, it is determined whether the child list ID of the attribute in the object is 1 (i.e., whether a child list exists) (step S34). If the child list ID is 1, the child list ID is read (step S35). If it is determined in step S34 that there is no child list, or after the child list ID has been read in step S35, the information information of that entry (entry specific information) is read (step S36), the counter value is counted up (step S37), and the process returns to the determination in step S32. Then, if it is determined in step S32 that the total number of entries and the counter count value are equal, a command to close this information list is sent, and reading is terminated (step S38). Next, if it is determined that there is a child list in the information list,
The process for reading the information child list will be described with reference to the flowchart in Figure 27. First, the child list ID read from the information list in step S35 is specified, and a read-open command is sent to set the list in a readable state (step S41). In this state, it is determined whether the list type is writable (step S42), and if it is writable, the restrictions on entry writing are detected (step S43). If it is determined in step S42 that it is not writable,
After detecting the restriction on entry writing in step S43, it is detected from the attribute whether the entry in the list has an object ID (step S4
4) The total number of entries is determined from the number of object entries, and a counter is initialized (step S45). Then, it is determined whether the total number of entries is greater than the count value of the counter (step S46).
(Step S46). In the initial state, the total number of entries is greater than the counter value. If the total number of entries is greater, it is determined whether an object ID exists (Step S47). If an object ID exists, the object ID is read (Step S48). Furthermore, it is determined whether the child list ID attribute in the object is 1 (i.e., whether a child list exists) (Step S49). If the child list ID is 1, the child list ID is read (Step S50). Then, the information information of that entry (entry specific information) is read (Step S51), the counter value is incremented (Step S52), and the process returns to the determination in Step S46. If the determination in Step S46 is that the total number of entries and the counter value are equal, a command to close the information list is sent, and reading is terminated (Step S53). 24 to 27, the process of reading a descriptor has been described. However, for writable descriptors, data can be written by issuing a write command while specifying the list position in the same manner as the read process. In this way, by providing a bulletin board subunit in one device connected by an IEEE 1394 bus line, and hierarchically structuring the descriptors that make up that subunit, and by determining each board and information from the highest-level descriptor, the devices connected by the bus line can efficiently share and control the data written in the bulletin board subunit. For example, as shown in FIG. 2, by providing a bulletin board subunit (BBS) 4 on the DVCR 200 side, the BBS controller 5 in the IRD 100 connected to the DVCR 200 by the bus line 1 can read the DBS 4 and determine the setting status of the programmed recording on the DVCR 200 in accordance with the procedures shown in the flowcharts of FIG. 24 to 27. By reading this BBS4, for example, the IRD 10
When reception is required by the tuner in BBSID, the appropriate operation is executed. Basic information such as the start time of this scheduled recording is written directly to the resource schedule board, which is directly indicated by the root list ID in the BBSID, which is the highest level descriptor, so that the information can be obtained quickly. For example, information accompanying scheduled recording is written to the information list descriptor, so by reading the information written in each information list descriptor, details about the scheduled recording can be known. For example, details such as the title and content of the program (program) scheduled for recording can be known. For example, in the case of digital broadcasts received by the IRD 100, information such as the program title and content can be obtained by using data called EPG (Electronic Program Guide) superimposed on the broadcast data. Furthermore, the information set in each descriptor and resource schedule board includes the object I
By setting "D", the correspondence between the various pieces of information can be easily understood. Furthermore, the BBS controller 5 in the IRD 100 can write data to the BBS 4 to set a new recording reservation. In this case, data is written to a writable descriptor, and by reading and judging the writable capacity information in the descriptor, it is possible to determine how much data can be written and set the appropriate write. Furthermore, by restricting writing to the descriptor set in the BBS, for example, by storing detailed information about a scheduled recording set in the DVCR 200 in a write-restricted descriptor, the BBS controller 5 in the IRD 100 cannot modify the scheduled recording, thereby ensuring accurate protection of the scheduled recording. The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit and scope of the present invention. For example, in the above embodiment, the BBS (Bulletin Board Subunit) is used as an example for writing information about recording reservations, but other data that needs to be made public via the bus line may be written in a similar hierarchically structured descriptor in the BBS. Also, the devices that use the BBS may include electronic devices other than the IRD and DVCR mentioned above (various video devices, audio devices, etc.).
In the above-described embodiment, the bus line connecting the devices can also be applied to the I/O.
Although the bus line is of the EEE1394 standard, bus lines of other standards may also be used. In this case, in addition to a bus line connected by wire, a wireless transmission path may be used to transmit data wirelessly between multiple devices.

[Brief explanation of the drawings]

FIG. 1 is a diagram illustrating the configuration of a conventional network device. FIG. 2 is a diagram illustrating the configuration of a network device according to an embodiment of the present invention. FIG. 3 is a block diagram illustrating an example of the configuration of a digital satellite receiver. FIG. 4 is a block diagram illustrating an example of the configuration of a video recording/playback device. FIG. 5 is an explanatory diagram illustrating an example of a frame structure in the IEEE 1394 standard. FIG. 6 is an explanatory diagram illustrating an example of the structure of an address space in the CRS architecture. FIG. 7 is an explanatory diagram illustrating an example of the location, name, and function of major CRSs. FIG. 8 is an explanatory diagram illustrating an example of the configuration of a plug control register. FIG. 9 is an explanatory diagram illustrating an example of the configuration of oMPR, oPCR, iMPR, and iPCR. FIG. 10 is an explanatory diagram illustrating an example of the relationship between plugs, plug control registers, and transmission channels. FIG. 11 is an explanatory diagram illustrating an example of a data structure based on a hierarchical structure of descriptors. FIG. 12 is an explanatory diagram illustrating an example of the data structure of a descriptor. FIG. 13 is an explanatory diagram illustrating an example of the generation ID in FIG. 12. FIG. 14 is an explanatory diagram illustrating an example of the list ID in FIG. 12. FIG. 15 is an explanatory diagram illustrating an example of a stack model for AV/C commands. FIG. 16 is an explanatory diagram showing an example of the relationship between commands and responses of AV/C commands. FIG. 17 is an explanatory diagram showing an example of the relationship between commands and responses of AV/C commands in more detail. FIG. 18 is an explanatory diagram showing an example of the data structure of an AV/C command. FIG. 19 is an explanatory diagram showing a specific example of an AV/C command. FIG. 20 is an explanatory diagram showing a specific example of commands and responses of an AV/C command. FIG. 21 is an explanatory diagram showing an example of the configuration of a BBS (Bulletin Board Subunit). FIG. 22 is an explanatory diagram showing an example of the data structure of a portion of the BBS shown in FIG. 21. FIG. 23 is an explanatory diagram showing an example of the data structure of another portion of the BBS shown in FIG. 21. FIG. 24 is a flowchart showing an example of a process for reading a board shown in a BBS. FIG. 25 is a flowchart showing an example of a process for reading a board list entry. FIG. 26 is a flowchart showing an example of a process for reading an entry in an information list. FIG. 27 is a flowchart showing an example of a process for reading an information child list. FIG. 28 is an explanatory diagram showing an example of a list type. Fig. 29 is an explanatory diagram showing an example of the data structure of an open command. Fig. 30 is an explanatory diagram showing an example of the data structure of a read command. Fig. 31 is an explanatory diagram showing an example of the data structure of a write command. Fig. 32 is an explanatory diagram showing an example of the data structure of a close command.

───────────────────────────────────────────────────── Continued from the front page (81) Designated Countries EP(AT,BE,CH,CY, DE, DK, ES, FI, FR, GB, GR, IE, I T, LU, MC, NL, PT, SE), OA (BF, BJ , CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP(GH, GM, K E, LS, MW, SD, SL, SZ, TZ, UG, ZW ), UA(AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AE, AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, CA, CH, CN, C R, CU, CZ, DE, DK, DM, EE, ES, FI , GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP, KE, KG, KP, KR, K Z, LC, LK, LR, LS, LT, LU, LV, MA , MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG, SI, S K, SL, TJ, TM, TR, TT, TZ, UA, UG , US, UZ, VN, YU, ZA, ZW (Note) This publication is based on the international publication by the International Bureau of International Trade and Industry (WIPO). Please note that the effect of the international publication of the Japanese-language patent application (Japanese-language utility model registration application) related to this publication arises pursuant to Article 184-10, Paragraph 1 of the Patent Act (Article 48-13, Paragraph 2 of the Utility Model Act), and is unrelated to this publication.

Claims (12)

[Claims] [Claim 1] An information processing method for transmitting information between multiple devices connected via a network, comprising: setting an information disclosure data storage unit that discloses specified information to devices connected via the network; configuring the information disclosure data storage unit in a specified hierarchically structured descriptor format; storing the specified information in a board set in the descriptor format; directly indicating the storage location of the specified board with the highest descriptor in the hierarchical structure; and storing information related to the specified information in an information area indicated by tracing the hierarchical structure from the highest descriptor. [Claim 2] An information processing method according to claim 1, wherein the information area is set to an area where information can be written from devices other than the device to which the descriptor is set, and an area where writing of information from other devices is restricted. 3. The information processing method according to claim 2, wherein when an area in which the information can be written is set, information relating to the writable capacity is added to the descriptor. [Claim 4] An information processing method as described in claim 1, wherein an ID is added to each piece of information stored on the specified board, and a common ID is also added to each piece of information stored in the information area, thereby enabling correspondence between the information stored on the board and the information stored in the information area. [Claim 5] An information processing system for transmitting information between multiple devices connected via a network, wherein a first device connected to the network is provided with an information disclosure data storage unit that discloses specified information to devices connected via the network, and a control unit that reads or writes the data stored in the information disclosure data storage unit by receiving a specified command via the network, and a control unit that issues a command to a second device connected to the network instructing it to read or write data stored in the information disclosure data storage unit, wherein data is stored in the information disclosure data storage unit provided in the first device in a specified hierarchically structured descriptor format, the specified information is stored in a board set in the descriptor format, the highest descriptor in the hierarchical structure directly indicates the storage location of the specified board, and information related to the specified information is stored in an information area indicated by tracing the hierarchical structure from the highest descriptor. 6. In the information processing system according to claim 5, the information area in the information disclosure data storage unit of the first device contains:
An information processing system, wherein an area to which information can be written from the second device and an area to which writing of information from the second device is restricted are set. [Claim 7] In the information processing system described in claim 6, when an area in which information can be written is set as the information area, a storage area for information regarding the writable capacity is added to the descriptor, and the control unit of the second device determines the writable capacity. [Claim 8] An information processing system as described in claim 5, wherein an ID is added to each piece of information stored on a specified board in the information disclosure data storage unit of the first device, and a common ID is also added to each piece of information stored in the information area, and the control unit of the second device determines the correspondence between the information stored on the board and the information stored in the information area based on the ID. [Claim 9] An information processing device that transmits information to other devices connected via a network, comprising: an information disclosure data storage unit that discloses specified information to other devices connected via the network; and a control unit that reads or writes data stored in the information disclosure data storage unit by receiving specified commands via the network; data is stored in the information disclosure data storage unit in a specified hierarchically structured descriptor format; the specified information is stored in a board set in the descriptor format; the highest descriptor in the hierarchical structure directly indicates the storage location of the specified board; and information related to the specified information is stored in an information area indicated by tracing the hierarchical structure from the highest descriptor. [Claim 10] In the information processing device described in claim 9, the information area within the information disclosure data storage unit is set up as an area where information can be written from other devices and an area where writing of information from other devices is restricted. 11. An information processing apparatus according to claim 10, wherein when an area in which information can be written is set as the information area, a storage area for information relating to the writable capacity is added to the descriptor. [Claim 12] An information processing device as described in claim 9, wherein an ID is added to each piece of information stored on a specified board in the information disclosure data storage unit, and a common ID is also added to each piece of information stored in the information area.