CN1309361A - Apparatus having configuration read-only memory storing format informations - Google Patents

Abstract

An electronic device includes a configuration ROM that is directly accessible by other electronic devices and stores functions related to itself as keys. Information about the subunits within the electronic device may also be stored as keys in the configuration ROM. The information on each subunit includes information indicating the format of data that can be handled by these subunits, information indicating the type of these subunits, and the like. Since the information about these subunits is stored as a key in a configuration ROM that can be directly accessed by other electronic devices, even if these electronic devices operate according to different protocols, they can easily read from the configuration ROM. Read information about these subunits in .

Description

Device with configuration ROM for storing format information

This invention relates to electronic equipment used on video equipment, audio equipment, etc., that can operate according to a specific protocol, such as "Audio/Video Control ("AV/C"). An electronic device with direct device access memory that stores information about subunits that is readily accessible to other electronic devices even if they operate according to a different protocol.

A plurality of electronic devices operating according to different protocols can be interconnected by a common bus, such as an IEEE (Institute of Electrical and Electronics Engineers) 1394 bus.

An electronic device (unit) functioning as an IEEE 1394 node, such as a video recorder, may include subunits and a configuration read-only memory ("ROM") in which various information about these subunits is stored. Other electronic devices can directly access the configuration ROM through the IEEE 1394 bus.

However, the information in the configuration ROM containing information about each subunit of a device operating under a specific protocol, such as the AV/C protocol, is inconsistent with that of a device operating under a different protocol. In particular, the information in the configuration ROM related to the specific protocol (AV/C) of the device cannot be accessed by other devices operating according to a different protocol.

If there is direct access to the above-mentioned configuration ROM, it is even more necessary that information related to the operating protocol of the electronic device, such as information about subunits, can be accessed by other electronic devices that may operate according to different protocols.

It is therefore an object of the present invention to provide an electronic device in which information about a subunit(s) of the device can be easily obtained by other electronic devices even operating according to different protocols. Other objects and advantages of the invention will be apparent, and some will be learned from the description and drawings.

The electronic equipment of the present invention includes a storage device for storing functions related to its own electronic equipment as keywords, and the storage device can be directly accessed by other electronic equipment; and at least one subunit, wherein the storage device stores the functions related to the subunit The information of the unit is stored as a key.

The present invention may include storage means that stores functions related to its own electronic equipment as keys, and the storage means can be directly accessed by other electronic equipment. If its own electronic equipment is an IEEE 1394 node, the storage means may be, for example, a configuration ROM. The storage means may store information about a sub-unit within the electronic device (or "unit") as a key. The information on the subunit may include information indicating the format of data that can be handled by a subunit, information indicating the type of a subunit, and the like.

Since the information about the subunit is stored as a key in a storage device that can be directly accessed by other electronic equipment, even if the other electronic equipment operates according to a different protocol, the other electronic equipment can be easily accessed from the The information about the subunit is read from the above-mentioned storage device.

In addition, the electronic equipment of the present invention may further include a storage device storing a seller or a model name in a minimum ASCII (American Standard Code for Information Interchange) format. Thus, the electronic equipment for which the minimum ASCII is valid can easily display a seller or a model name.

For a better understanding of the present invention, refer to the following description and accompanying drawings, wherein:

Figure 1 is a block diagram representing a network system interconnected using IEEE 1394;

Fig. 2 represents the periodic structure of the transmission data of the device utilizing IEEE 1394 system connection;

Figure 3 is a diagram representing the address space structure of the CSR architecture;

Fig. 4 represents the structure of PCR;

Figures 5(A) to 5(D) represent the structures of oMPR, oPCR, iMPR and iPCR, respectively;

Fig. 6 represents the relation between plug (plug), plug control register and synchronous channel;

Figure 7 shows the relationship between control commands and their responses;

Figure 8 shows in detail the relationship between the command and response of Figure 7;

Fig. 9 shows an example of the packet structure of the synchronous transfer packet of an embodiment of the present invention;

Fig. 10 shows an example of the packet structure of the asynchronous transfer packet of an embodiment of the present invention;

FIG. 11 is a diagram representing a data structure of a configuration ROM;

Fig. 12 is a diagram representing a data structure of a bus information block;

FIG. 13 is a diagram representing types of subunits stored as keys;

FIG. 14 is a diagram showing correspondence between subunits and keywords;

Fig. 15 is a diagram showing the correspondence between data formats and keywords;

FIG. 16 is a diagram representing an example in which format information of data that can be processed by a subunit is stored as a key;

An embodiment of the present invention is described below with reference to the accompanying drawings:

FIG. 1 shows a network system in which a plurality of nodes are interconnected using an IEEE 1394 bus 20. In the network system shown in FIG. 1, an integrated receiver decoder ("IRD") 10 and a video deck (video deck) 100 are connected to an IEEE 1394 bus 20. IRD 10 and video recorder 100 may each be an IEEE 1394 node. A receiving antenna 30 and a monitor 40 are connected to the IRD 10. The receiving antenna 30 is also connected to the video recorder 100 .

As described above, the video recorder 100 is an IEEE 1394 node and can operate according to the AV/C protocol. The video recorder 100 may include a tuner 110 and a tape recording/reproducing section 120 as subunits, and may also include a configuration ROM 130 storing information on the video recorder. In addition, video recorder 100 may be capable of handling "MPEG2" Transport Stream" (Moving Picture Experts Group) and "Digital VCR" (Video Cassette Recorder) video data formats.

Figure 2 shows the periodic structure of data transmitted by devices connected according to IEEE 1394. In IEEE1394, data is divided into packets and transmitted in a time-division manner at a cycle of 125 μs (microsecond). This cycle is established by a cycle start signal provided by the master cycle capable electronics. The isochronous packet secures the bandwidth necessary for transmission from the beginning of each cycle (time unit is called bandwidth). Thus, isochronous transmission guarantees data transmission within a fixed time. However, if a transmission error occurs, the data will be lost with no protection mechanism.

Electronic devices occupying the bus as a result of arbitration transmit asynchronous packets during the time not used for isochronous transfers of each cycle. Asynchronous transfers ensure safe transfers by utilizing acknowledgments and retries, but transfer timing will be variable.

In order for predetermined electronic devices to perform isochronous transfers, these electronic devices must have a synchronization function. In addition, at least one of these electronic devices must have a main cycle function. Also, at least one electronic device connected to the IEEE 1394 serial bus has an isochronous resource manager function.

IEEE 1394 may be based on a "Control and Status Register ("CSR") architecture with a 64-bit address space as specified in ISO/IEC (International Organization for Standardization/International Electrotechnical Commission) 13213. FIG. 3 shows the structure of an address space conforming to the CSR structure. The upper 16 bits can form the node ID representing each node on the IEEE1394 bus. The remaining 48 bits can be used to specify the address space assigned to each node. In addition, these upper 16 bits can be divided into 10 bits of the bus ID and 6 bits of the actual ID (node ID in a narrow sense).Since values with all bits set to 1 can be used for special purposes, they can specify 1023 buses and 63 nodes.

In the address space of 256 terabytes specified by the lower 48 bits, the space specified by the upper 20 bits can be divided into initial register spaces (Initial Register Space) used in 2048-byte CSR-specific registers, IEEE 1394-specific registers, etc. ), Private Space, Initial Memory Space, etc. If the space specified by its upper 20 bits is an initial register space, etc., then the space specified by the lower 28 bits can be used as: initial unit space (Initial Unit Space) used in configuration ROM 130 and dedicated to a node, plug control Register (Plug ControlRegister("PCR")), etc. The above-mentioned configuration ROM 130 based on a general ROM format may be set in the range of addresses 400h to 800h in the initial register space.

Although every electronic device has a CSR as shown in FIG. 3, only those contained in the isochronous resource manager are valid as far as bandwidth available registers are concerned. In other words, bandwidth-available registers are actually only contained by isochronous resource managers.

If no bandwidth is allocated in synchronous communication, the maximum value is stored in the bandwidth available register, and its value is decremented every time bandwidth is allocated.

Each bit of the channel availability register between offsets 224h and 228h corresponds to channel numbers 0 to 63, respectively. If a bit is equal to zero, it indicates that the corresponding channel has been allocated. In this case, only the channel availability register of the electronic device operating as an isochronous resource manager is valid.

In order to control the input and output of each device through the interface, each device has a PCR (plug control register) specified by IEC 61883 in the initial unit space shown in FIG. 3 from address 900h to 9FFh. One incarnation of the concept of a plug is to form a signal path that is logically similar to an analog interface.

Fig. 4 shows the structure of PCR. The PCR has an output plug control register ("oPCR") to represent an output plug and an input plug control register ("iPCR") to represent an input plug. In addition, the PCR has an input master plug register ("oMPR") and an input master plug register ("iMPR") that represent information specific to each device on either the output plug or the input plug. Each device may not have multiple oMPRs and iMPRs, but may have multiple oPCRs and iPCRs corresponding to each plug. The PCRs shown in Figure 4 have 31 oPCRs and iPCRs, respectively. The flow of isochronous data is controlled by manipulating the registers corresponding to these plugs.

5A to 5D show the structures of oMPR, oPCR, iMPR and iPCR: FIG. 5A shows the structure of oMPR; FIG. 5B shows the structure of oPCR; FIG. 5C shows the structure of iMPR; FIG. 5D shows the structure of iPCR. The 2-bit data rate capability field storage on one side of the oMPR and iMPR indicates the maximum transmission speed of isochronous data that can be transmitted or received by the device. The field of broadcast channel base of oMPR specifies the channel number used for broadcast output.

The 5-bit number of output plugs area at the other end of the oMPR stores a value indicating the number of output plugs owned by the relevant device, that is, the number of oPCRs. The 5-bit number of input plugs area at the other end of the iMPR stores a value indicating the number of input plugs possessed by the relevant device, that is, the number of iPCRs. The areas of the non-permanent extension field and the permanent extension field are areas for future extension.

Each line field at one end of the oPCR and iPCR indicates the usage status of the plug. In other words, a value of 1 means the plug is online, while a value of 0 means the plug is offline. The value of each broadcast connection counter of oPCR and iPCR indicates whether a broadcast connection exists (1) or does not exist (0). The value of each point-to-point connection counter (6 bits wide) of oPCR and iPCR indicates the number of point-to-point connections owned by the associated plug. The value of each channel number (6 bits wide) of oPCR and iPCR indicates the synchronization channel number to which the associated plug is connected. The value of the data rate (2 bits wide) of the oPCR indicates the actual transmission speed of the isochronous packets output by the associated plug. The code stored in the overhead ID (4-bit width) area of oPCR indicates the bandwidth of the overhead of the isochronous communication. The value of the payload (10 bits wide) of oPCR indicates the maximum value of data contained in an isochronous packet that the associated plug can handle.

Figure 6 shows the relationship between plugs, plug control registers and isochronous channels. AV (Audio Visual) equipment 50 to 52 are connected to each other by an IEEE 1394 serial bus. Synchronous data whose channel is specified by oPCR(1) (of oPCR(0) to oPCR(2)) and whose transmission speed and number of oPCRs are determined by oMPR of the AV equipment 52 is sent to channel 1 of the IEEE 1394 serial bus . The AV equipment 50 reads and stores isochronous data sent to channel 1 of the IEEE 1394 serial bus. Likewise, the AV device 51 transmits isochronous data to channel 2 specified by oPCR(0), and the AV device 50 reads the isochronous data of channel 2 specified by iPCR(1) and stores it.

The AV/C command set employed in the audio system shown in FIG. 1 will be described below with reference to FIGS. 7 and 8. FIG.

Fig. 7 shows control commands and responses sent asynchronously. As shown in FIG. 7, the controlling side is represented by "controller" and the controlled side is represented by "target". Transmission of a control command or a response to the command is performed between electronic devices using a write transaction of asynchronous transmission over IEEE 1394. The target receives the data and returns an acknowledgment (ACK) to the controller to confirm the receipt of the data.

FIG. 8 shows the relationship between the control commands and responses shown in FIG. 7 in more detail. Electronic device A is connected to electronic device B through the IEEE 1394 bus. Electronic device A is the controller and electronic device B is the target. Both electronic device A and electronic device B have a command register and a response register, each of 512 bytes. As shown in FIG. 8, the controller (device A) transmits a command by writing a command message into the command register 123 of the target (device B). Conversely, the target (device B) transmits a response by writing a response message to the response register 122 of the controller (device A). Control information is then exchanged using these two messages.

FIG. 9 is a diagram showing a part of an isochronous transfer packet used for the above-mentioned isochronous transfer. The packet is assigned a header which occupies the first 32*2 bits and includes synchronization mode (sy), packet code (tcode), channel, flag, data length, and error correction code (CRC). The continuous packet count value (DBC), reserved (RSV), indicating whether there is a source packet header (SPH), the division number (FN) of the source packet, and the data when dividing the fixed-length data to assign each packet The block size (DBS), its own identification code (SID), and the like are assigned to the following 32 bits. A recording area (SYT) such as a time stamp, a sampling frequency (FDF) of transmitted data, a transmission format (FMT) and the like are allocated to the subsequent 32 bits. Further, transmitted data composed of source data of a unit of 32 bits is assigned to the next 32 bits, and at the end of these transmitted data is an error correction code (CRC).

Furthermore, in this example, one bit at a specific position in the sampling frequency (FDF) region composed of 8 bits (one bit at a position surrounded by a dotted line in FIG. Rate is Flag Controlled (FC). If the flag (FC) is a "1" signal, it means that the transmission rate controlled mode has been entered. If the flag (FC) is a "0" signal, it means entering a mode in which the transmission rate is not controlled. In the following description, the mode in which the transmission rate is controlled is called a flow control mode.

The link block (not shown) of video recorder 100 of Fig. 1 adds digital audio signal (DA), digital video signal (DV) etc. to this isochronous transmission packet according to fixed unit, and through input-output circuit (not shown) Send it to the bus 20.

FIG. 10 is a diagram showing an asynchronous transfer packet for one-to-one asynchronous communication using the above-mentioned control commands and the like. The input-output circuit of the video recorder 100 sets an address, etc. indicating its own node and bus number, etc., on a packet to transmit it. Specifically, 32 bits from the front of the packet are assigned to the priority (priority) of the packet, the code (tCode) of the packet, the retry code (rt) of the packet, the The label (tLabel), the transmission speed (spd) and the identification data (imm) representing the relationship of successive packets. In addition, data specifying the address of the destination node (destination offset high, destination offset low) and data indicating the destination node and the bus (destination ID) are allocated. The data length (data length) and the like of the transmission data are also allocated, and these transmission data are allocated in units of 32 bits.

The link block of the video recorder 100 receives packets of one-to-one communication received by the input-output circuit, and notifies a processing device (not shown), such as a host computer or an integrated central processing unit ("CPU"), of the data assigned to the packet. In this way, various control commands transmitted from a device (not shown) to the video recorder 100 are informed to the processing means.

As regards data communication between devices connected in accordance with IEEE 1394, see co-pending U.S. Patent Application No. 09/490,827, filed January 25, 2000, which is incorporated herein by reference.

Fig. 11 shows the data structure of configuration ROM 130 shown in Fig. 1. The configuration ROM 130 may contain a bus information block "Bus information block", a root directory "Root Directory", an instance directory "Instance Directory" and a unit directory "Unit Directory".

FIG. 12 shows the data structure of the bus information block shown in FIG. 11. The first 5 nibbles of ROM 130 may contain a block of bus information. Unique values can be assigned to the 64-bit "node-vendor-id (node vendor ID)", "chip-id-hi (chip ID high)", and "chip-id-lo (chip ID)" in the bus information block. ID Low)" to distinguish devices from each other. The "node-vendor-id" may be assigned to the manufacturer by IEEE/RAC (Registration Administration Committee). "chip-id-hi" and "chip-id-lo" may be an ID uniquely assigned by "node-vendor-id" of 40 bits in total.

Referring back to FIG. 11 , the Vendor ID may be located at the entry of the root directory "Vendor (manufacturer)". A "Textual descriptor" may accompany the "Vendor" entry. The position of "Textual descriptor" can be represented by "Descriptor leaf offset (descriptor branch offset)". In an embodiment of the present invention, the minimum ASCII character representing the manufacturer may be located at the "Textual descriptor".

Or, as shown in FIG. 13, the position "Descriptor Directory offset (descriptor directory offset)" representing "Descriptor Directory (descriptor directory)" may be located at the root directory. The "Descriptor leaf offset" indicating the location of the mandatory ("Mandatory") "Textual descriptor" may be located at the "Descriptor Directory". "Descriptor leaf offset" can also indicate the position of optional ("Optional") "Texture descriptor", "Icon descriptor (icon descriptor)", etc. In this case, the minimum ASCII characters may be located at the optional ("Optional") "Texturedescriptor". Also, icon data indicating a manufacturer may be located at "Icon descriptor".

Referring again to FIG. 1, the example directory may be a directory representing some examples of the functionality of the electronic device itself. The root directory may contain an "Instance directory offset" representing the location of the instance directory. In addition, the sample directory can also contain a "Keyword leaf offset" indicating the location of the "Keyword leaf" and a "Unit directory offset" indicating the location of the unit directory .

A node serving as an access unit on the IEEE 1394 bus may include multiple units that can be operated independently, while some nodes may share an address space. A unit directory may represent the version and location of the unit's software. Incidentally, although the locations of the bus information block and the root directory are fixed, other blocks can be determined using offset addresses.

Information representing types of all subunits within the electronic device may be located at "Keyword leaf" as a keyword. The keyword can be represented by capital letters "A to Z" of the alphabet, numeric values "0 to 9" and a hyphen "-". Fig. 14 shows some examples of correspondence between subunit types ("Subunit Type") and keywords ("Keyword"). In an embodiment of the present invention, the video recorder 100 may include a tuner 110 and a tape recording/reproducing section 120 as subunits inside it. For this reason, "TUNER" representing the tuner 110 and "TAPE (tape)" representing the tape recording/reproducing section 120 may be placed at "Keyword leaf" as keywords.

In addition, information indicating the overall format that can be processed by subunits within the electronic device can be located at the "Keyword leaf" as a keyword. Fig. 15 shows some examples of correspondence between formats ("Format") and keywords ("Keyword"). In the manner of carrying out the present invention, video data in the formats of "MPEG 2 (Moving Picture Experts Group) Transport Stream" and "Digital VCR (Video Recorder)" can be handled. For this purpose, "MPEG 2-TS" representing "MPEG 2 Transport Stream" and "DV" representing "Digital VCR" can be placed at the "Keyword leaf" as keywords.

Returning to Figure 11, the root directory may contain a "Unit directoryoffset" representing the location of the unit directory. The unit directory may contain entries for "Specifier-ID (specifier ID)", "Version (version)" and "Model (model)". The model ID can be located at the "Model" entry. A "Textualdescriptor" can accompany the "Model" entry. The position of "Textual descriptor" can be represented by "Descriptor leaf offset". In an embodiment of the present invention, the minimum ASCII characters representing the model name may be located at the "Textual descriptor".

Alternatively, as shown in Figure 16, the "DescriptorDirectory offset" indicating the location of the "Descriptor Directory" can be located at the root directory, for example, the "Descriptor leaf offset" indicating the location of the mandatory ("Mandatory") "Textualdescriptor" can be located at the "Descriptor Directory" , the "Descriptor leaf offset" indicating the position of the optional ("Optional") "Textual descriptor", "Icon descriptor", "Modifiabledescriptor (modifiable descriptor)", etc. may be located at the same place. In this case, the minimum ASCII characters representing the model name can be located at the mandatory ("Mandatory") "Textual descriptor". The icon data of the model can be located at "Icondescriptor". Also, other data representing the model number may be located at the "Modifiable descriptor".

As described above, according to an embodiment of the present invention, information indicating the type of each subunit in the video recorder can be stored as a key in the configuration ROM 130. Also, information indicating the format of data that can be processed by each subunit in the video recorder 100 may also be stored in the configuration ROM 130. The configuration ROM 130 is directly accessible by other electronic devices operating under a protocol other than the AV/C protocol. Therefore, in the network system of FIG. 1, even when, for example, the IRD 10 can operate according to a protocol other than the AV/C protocol, the IRD 10 can directly access the configuration ROM 130 of the video recorder 100, and can easily obtain Format information of data handled by subunits within the video recorder 100 .

By the way, although in the above-described embodiments of the present invention, the information on each subunit stored in the configuration ROM 130 is information indicating the type of each subunit and information indicating a data format that can be processed by these subunits, However, the present invention is not limited thereto.

Also, although in the invention described above, the invention is applied to the video recorder 100, it goes without saying that the present invention can be equally applied to other electronic devices including a similarly configured ROM.

According to the invention, since the information about the subunits is stored in memory means which can be directly accessed even by other electronic devices operating according to different protocols, this information can be easily obtained by these electronic devices. In addition, since the electronic device includes a memory device storing the maker or model name in minimum ASCII, the maker or model name can be easily displayed if the electronic device is an electronic device for which the minimum ASCII is valid.

It can be seen that, except the purpose clearly seen from the above description, the above-mentioned purpose has been effectively realized, because some improvements can be made in implementing the above-mentioned method and the above-mentioned structure without departing from the spirit of the present invention and not exceeding its scope, It is therefore to be realized that all matter contained in the above description, except that shown in the accompanying drawings, is illustrative and not restrictive.

It should also be realized that the appended claims are intended to cover both generic and specific features of the invention described herein and also all expressions of the invention which, by language interpretation, may be considered to be within their scope.

Claims (28)

1. one kind is carried out the equipment that the operation handlebar data send bus to according to first agreement, and this equipment comprises:

The DIU data interface unit of input and output data; And

Store the data storage device of the information of closing the equipment that relates to first agreement, this data storage device can be carried out access by DIU data interface unit by the miscellaneous equipment of operating according to second agreement.

2. according to the equipment of claim 1, first agreement wherein is a host-host protocol.

3. according to the equipment of claim 1, first agreement wherein is the function control protocol.

4. according to the equipment of claim 3, first agreement wherein is the AV/C agreement.

5. according to the equipment of claim 1, data storage device is wherein stored information as key word.

6. according to the equipment of claim 1, data storage device wherein is with the hierarchical form canned data.

7. according to the equipment of claim 1, information wherein comprises the information of the function type of indication equipment.

8. according to the equipment of claim 7, also comprise one or more subelements, the information of the function type of indication equipment wherein comprises the information of the type of representing at least one these subelement.

9. according to the equipment of claim 1, data storage device wherein is with the mode canned data of minimum ASC II.

10. according to the equipment of claim 9, data storage device wherein comes canned data with letter.

11. according to the equipment of claim 9, data storage device wherein comes canned data with numeral.

12. according to the equipment of claim 9, data storage device stores trade name wherein.

13. according to the equipment of claim 9, data storage device stores model name wherein.

14. according to the equipment of claim 9, information wherein comprises the information of representing data layout.

15. one kind obtains the method for data from carry out apparatus operating according to first agreement, this equipment comprises data storage device and DIU data interface unit, and this method may further comprise the steps:

The information stores of the relevant equipment that relates to first agreement in data storage device; And

Come acquired information by DIU data interface unit access data memory storage, data storage device wherein can be carried out access by DIU data interface unit by the miscellaneous equipment of operating according to second agreement.

16. according to the method for claim 15, first agreement wherein is a host-host protocol.

17. according to the method for claim 15, first agreement wherein is the function control protocol.

18. according to the method for claim 17, first agreement wherein is the AV/C agreement.

19. according to the method for claim 15, data storage device is wherein stored information as key word.

20. according to the method for claim 15, data storage device wherein is with the hierarchical form canned data.

21. according to the method for claim 15, information wherein comprises the information of the function type of indication equipment.

22. according to the method for claim 21, equipment wherein also comprises one or more subelements, and the information of the function type of indication equipment comprises the information of the type of representing at least one these subelement.

23. according to the method for claim 15, data storage device wherein is with the mode canned data of minimum ASC II.

24. according to the method for claim 23, data storage device wherein comes canned data with letter.

25. according to the method for claim 23, data storage device wherein comes canned data with numeral.

26. according to the method for claim 23, data storage device stores trade name wherein.

27. according to the method for claim 23, data storage device stores model name wherein.

28. according to the method for claim 15, information wherein comprises the information of representing data layout.

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