JPH1127299A - Electric appliance and protocol switching method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the equipment which is connected to a bus to respond to a plurality of protocols on the bus. SOLUTION: When a CD player is to be controlled, for example, information on a subunit identifier descriptor in the CD players is read out (step S1) and a disk list entry is read out (step S2). Then, it is determined on the basis of the read information or the like whether or not a disk can operate by an AV/C command (step S3) and, if the answer is Yes, a control is performed by the AV/C command (step S4). If No is obtained at the step S3, it is determined whether the disk can operate by other command (step S5); if the answer is Yes, control is performed by the command (step S6) and when No, the control is not performed (step S7).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to, for example, IEEE 1
The present invention relates to a bus such as a 394 high-speed serial bus (hereinafter referred to as a 1394 serial bus) on which a plurality of protocols can be loaded, and more particularly, to a technique for enabling an electronic device connected to the bus to support a plurality of protocols.

[0002]

2. Description of the Related Art Personal computers (hereinafter referred to as PCs) and digital video cassette recorders (hereinafter referred to as DVCRs).
), Electronic devices such as digital television receivers (hereinafter referred to as devices) are connected by a 1394 serial bus,
Communication systems that transmit and receive digital video signals, digital audio signals, and control signals in packets between these devices have been considered.

In this communication system, an isochronous (hereinafter referred to as Is) system for periodically transmitting real-time data such as digital video signals and digital audio signals between devices.
Och) communication and asynchronous (hereinafter, Asynch) communication for transmitting a control signal such as an operation control command of a device or a connection control command between devices irregularly as necessary.

In the above-mentioned communication system, commands used for controlling AV (Audio Visual) equipment are FCP (Function Control P).
There is an AV / C (audio-visual / control) command set on the Internet. In addition, SBP is used as a protocol between the PC and its peripheral devices.
(Serial Bus Protocol)
PC control commands such as SCSI-3 can be used.

FIG. 11A shows a CD player (hereinafter referred to as a CD player).
P) is connected to an audio amplifier via a 1394 serial bus. In this system, CDP is used as audio equipment. Then, a CD-DA (Digital Au) is set according to the AV / C command set.
It is possible to perform mechanical control such as play and pause of the game (dio), and control based on content such as selection by music.

FIG. 11B shows a system in which a disk driver is connected to a PC via a 1394 serial bus. In this system, a disk driver is used as a peripheral device of a PC. In this system, P such as SCSI
It is possible to access a file such as a CD-ROM using the C control command.

[0007]

[0005] Inserted media (CD-DA, CD-RO, etc.) like a disk driver
Devices whose applications differ depending on M)
Supporting only commands of either protocol limits the application. AV /
With the C command set, the mechanical control of the CD-DA and the control by the content are possible as described above. It also supports control from multiple controllers (devices that send commands) and operation of the main unit. Conversely, reliable control from the controller is not guaranteed. Since the AV device is to be controlled, the CD-
Files such as ROM cannot be accessed.

On the other hand, PC control commands such as SCSI can access a file such as a CD-ROM. It also supports mechanical controls such as CD-DA play and pause. However, control from a controller (initiator) such as a PC is required for reliable one-to-one control.

Accordingly, an object of the present invention is to enable a device connected to a bus to support a plurality of protocols on the bus.

[0010]

According to the present invention, there is provided an apparatus connected to a bus capable of carrying a plurality of protocols, the apparatus comprising storage means for storing information on a protocol corresponding to the apparatus. It is a feature.

A protocol switching method for a device according to the present invention is a method of connecting a device capable of supporting a plurality of protocols to a bus capable of carrying a plurality of protocols, and switching a protocol used by the device. The target device reads information on a corresponding protocol and selects the protocol by referring to the information.

Further, the device according to the present invention is a device which is connected to a bus capable of carrying a plurality of protocols, and which supports a plurality of protocols and has a predetermined protocol among a plurality of protocols connected to the bus. It is characterized in that a device corresponding to only the protocol described above is handled as a subunit.

The protocol switching method for devices according to the present invention includes a first device capable of supporting a plurality of protocols on a bus capable of carrying a plurality of protocols, and a predetermined protocol among the plurality of protocols. A second device capable of handling and a third device capable of handling only another predetermined protocol among the plurality of protocols are connected, and the second device transmits a control command for the third device according to the predetermined protocol. The first command is transmitted to the first device, and the first device converts the received control command into the another predetermined protocol and transmits the same to the third device.

According to the present invention, information on a protocol supported by the device is stored in the first storage means. Then, when controlling another device, the other device reads this information and selects a protocol to be used based on the information.

According to the invention, the first device is the third device.
Equipment is treated as a subunit. Then, the first device receives a command of a predetermined protocol transmitted from the second device to the first device to control the third device, and converts the command to a protocol that the third device can support. After the conversion, it is transmitted to the third device.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows the configuration of a system to which the present invention is applied. This system uses PC1 as a device.
, A DVCR 2, a monitor device 3, a CDP 4, and an audio amplifier 5, and the respective devices are connected by 1394 serial bus cables 6 to 9. In this system, DVCR2, monitor 3, CDP
4 and the audio amplifier 5 correspond to AV / C commands. PC1 and CDP4 correspond to PC control commands. That is, CDP4 supports both AV / C commands and PC control commands.

FIG. 2 is an internal block diagram of the CDP 4 in FIG. In this CDP, the pickup 11,
The signal processing circuit 12, CD decoder 13, mechanical controller 14, servo circuit 15, motor 16, D / A converter 17, and CD-ROM decoder 18 are provided in a known CD player or a known CD-ROM drive. The description is omitted because it is not directly related to the present invention. The audio transmission block 19
When a CD-DA disc is set in the CDP, the digital audio signal decoded by the CD decoder 13 is processed according to an audio transmission protocol. Then, the output is converted into an Isoch packet by the 1394 interface 20 and transmitted to the 1394 serial bus.

Digital interface controller 21
When a CD-ROM disc is set in this CDP, the data decoded by the CD-ROM decoder 18 is processed according to the SCSI protocol. The output is output to A by the 1394 interface 20.
The packet is transmitted to the 1394 serial bus as a synch packet.

In the AV / C command set, there is a concept of selection by an object list (object_list). This concept is adopted in the disc subunit of the CDP, and a system such as a 200 CD changer can be selected. The disk subunit has an object list as shown in FIG. Each entry in the disc list corresponds to a slot in the changer. Therefore,
For a regular non-changer player, there is only one entry in the disc list. Each entry in the disc list has a child list called a track list. From the track list, the user can examine and select a song. The disc list and the track list are created by the system controller 23 based on the information written in the TOC area of the CD-DA when the CD-CA is set in the CDP, and are stored in the internal memory. Save it. Figure 4 shows the disk list
It is an example of an entry.

Here, in order to enable coexistence with a PC command, a subunit identifier descriptor (Subunit Id) as shown in FIG.
entifier Descriptor)
Media types supported by C command set,
And the types of media that can be supported by commands other than the AV / C command set. This subunit identifier descriptor can be provided as a part of the ROM in the system controller 23 of FIG. Instead of storing the information in the ROM in advance, it may be configured to be downloaded from a network or the like and stored.

In FIG. 5, the subunit type (s
In the (unit_type) field, whether the subunit has a drive function (Normal) or a drive corresponding to this subunit does not physically exist, and receives an AV / C command and performs control corresponding to the AV / C command to an external device. With functions to perform (Gate
way).

Also, the number of supported media (nu
mber_of_supported_medium_
In the (types) field, the number of media supported by the AV / C command set is written (FIG. 5).
M), followed by the media type (media
In the “m_type) field, the type of the supported media is written. Fig. 6 (1) shows the media
Here is an example of the type.

Further, in FIG. 5, another control command number (number_of_other_control)
_Commands) field describes the number of commands that can be supported by commands other than the AV / C command set (n in FIG. 5), and other control commands (other_command) fields following that field contain commands Information such as shown in FIG. 6 (2) is written every time.

Next, the command switching process in the controller will be described with reference to FIG. For example, when the monitor device 3 of FIG. 1 attempts to control the CDP 4, the monitor device 3 first reads out the information of the subunit identifier descriptor in the CDP 4 (step S1), and then reads the disc list entry. Read (step S2). These reads are made in 1394
AV / Async packet on serial bus
This is performed using the C command.

Next, the monitor device 3 determines whether the disc can be handled by the AV / C command (step S).
3). That is, it is determined whether or not the information written in the media type (medium_type) field of the subunit identifier descriptor read in step S1 includes the media type of the disc list read in step S2. to decide.

More specifically, the disk list entry refers to which disk is inserted into which slot of the CDP4. For example, if a CD-ROM disc is inserted, the media type and
CD-DATA (“0101”) is described in the field. If the CDP does not support the CD-ROM, the number of media (number) supported by the subunit identifier descriptor
_Of_supported_medium_type
s) The media type (medium) following the field
_Type) field does not include CD-DATA.

If YES in step S3, A
Control is performed by a V / C command (step S4).

If NO in step S3, it is determined whether the disc can be handled by another command (step S5). That is, the media type written in the other control command (other_command) field of the subunit identifier descriptor read in step S1 is the same as that of step S1.
It is determined whether or not the media type of the disk list read in step 2 is included.

For example, in the case where access by a SCSI command is supported, the specifications (o
ther_command_specificatio
At n), it can be seen that the SCSI command corresponds to CD-DATA. Then, in step S5, Y
In the case of ES, another control command (other
_Command) is controlled by a command written in the field (step S6).

If NO in step S5, this CD
Since P does not correspond to the set disk, no control is performed (step S7).

FIG. 8A shows another configuration of a system to which the present invention is applied. This system is based on IRD (Integr
attached Receiver Decoder) 32
, The hard disk device 31 and the monitor device 33 are connected by 1394 serial bus cables 34 and 35. Then, the IRD 32 controls the hard disk device 31 with a SCSI command. The control between the IRD 32 and the monitor device 33 is controlled by an AV / C command. In this system, as shown in FIG. 8B, the hard disk device 31 can be handled as a disk subunit, which is one subunit in the IRD 32. That is, it can be controlled by AV / C commands in the same manner as the IRD built in the hard disk.

FIG. 9 is a detailed block diagram of FIG. In the IRD 32 of this system, a front end 41, a demultiplexer 42, a video decoder 43, D
/ A converter 44, audio decoder 45, D / A
Since the converter 46 and the conditional access block 47 are known and have no direct relation to the processing of the control command, the description is omitted.

In this system, a tuner descriptor and an HD descriptor are provided in a memory 49 connected to a processor 48 in the IRD 32. Further, the processor 48 receives the AV / C command and the SCS
It has a function to convert between I commands. Monitor device 3
3 includes a processor 62 and a digital interface 61, and operates here as a controller (the transmitting side of the AV / C command). Further, the hard disk device 31 includes a processor 52 and a digital interface 5.
1 and a hard disk drive 53, and here operates as a SCSI command receiving side.

The processing of the IRD 32 shown in FIG. 9 will be described with reference to the flowchart of FIG.

The IRD 32 receives an AV / C command for the HD device 31 (Step S11). That is, the HD device 3 generated by the processor 62 in the monitor device 33
AV / C command for the digital interface 61
Into an Aynch packet on the 1394 serial bus, and the IRD via the 1394 serial bus cable 35.
32, where the AV / C commands are separated and input to the processor 48.

The processor 48 refers to the HD descriptor in the memory 49 and determines whether the disk subunit has a gateway function (step S1).
2). And if you do not have a gateway function,
“Not Implemente” of AV / C response
d ", and the digital interfaces 50 and 1394
The data is returned to the monitor device 33 via the serial bus cable 35 (step S13).

If YES in step S12, it is determined whether the HD device 31 can be controlled next (step S14). If the control is not possible, “REJECTED” of the AV / C response
Is returned (step S15). For example, the HD device 31
If the user is currently performing other work, control becomes impossible.

If it is determined in step S14 that control is possible, "INTERIM" of the AV / C response is returned (step S16).

Next, the HD AV / C command received in step S11 is converted into a SCSI command (step S17), and the HD device 31 is controlled (step S1).
8). That is, the SCSI command converted by the processor 48 is transmitted to the Aynch by the digital interface 50.
The packet is transmitted to the 1394 serial bus 34 as a packet,
Send to D device 31. The Aynch packet is received by the digital interface 51 in the HD device 31, where the SCSI command is extracted and sent to the processor 52. The processor 52 controls the HDD 53 according to the SCSI command. After controlling the HD, the processor 48 in the IRD 32 returns an AV / C response "ACCEPTED" (step S19).

As described above, the monitor device 33 can control the hard disk device 31 as a disk subunit built in the IRD 32 by AV / C commands.

[0042]

As described above, according to the present invention, a device connected to a bus can support a plurality of protocols on the bus. Thus, for example, A
When a medium that requires file access is inserted into an AV device controlled by the V / C command set, whether the AV device can access the inserted medium using another protocol is determined. It can be understood at the level of the AV / C command. Then, the controller can switch the control method based on this information.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a system to which the present invention is applied.

FIG. 2 is an internal block diagram of a CDP in FIG.

FIG. 3 shows objects and objects of a disk subunit.
It is a figure showing an example of a list.

FIG. 4 is a diagram showing an example of a disc list entry in the object list of FIG. 3;

FIG. 5 is a diagram illustrating a configuration example of a subunit identifier descriptor.

FIG. 6 is a diagram illustrating an example of specifications of a media type field and other commands in a subunit identifier descriptor.

FIG. 7 is a flowchart showing a command switching process.

FIG. 8 is a diagram showing another configuration of a system to which the present invention is applied.

9 is a block diagram showing a detailed configuration of the system shown in FIG.

FIG. 10 is a flowchart showing an IRD process in FIG. 9;

FIG. 11 is a diagram showing a connection form of CDP.

[Explanation of symbols]

1 PC, 2 DVCR, 3 33 Monitor device, 4
... CDP, 5 ... Audio amplifier, 6-9, 34, 35
1394 serial bus cable, 22 system controller, 31 hard disk drive, 32 IRD,
48 processor, 49 memory.

Claims (8)

[Claims] 1. An electronic device connected to a bus capable of carrying a plurality of protocols, the electronic device comprising: first storage means for storing information on a protocol corresponding to the electronic device. . 2. The electronic device according to claim 1, wherein the bus is an IEEE 1394 high-speed serial bus. 3. The electronic device according to claim 1, wherein the plurality of protocols are a protocol for an audiovisual device and a protocol for a computer peripheral device. 4. The electronic device according to claim 2, wherein the plurality of protocols are an AV / C command and a SCSI command. 5. The electronic apparatus according to claim 1, having a function of reproducing a digital information signal including a digital audio signal from a recording medium. 6. A method of connecting an electronic device capable of supporting a plurality of protocols to a bus capable of carrying a plurality of protocols, and switching a protocol used by the electronic device. A protocol switching method for an electronic device, wherein the electronic device reads information on a corresponding protocol and selects the protocol with reference to the information. 7. An electronic device connected to a bus capable of carrying a plurality of protocols, the device being compatible with the plurality of protocols and being connected to only a predetermined protocol among the plurality of protocols connected to the bus. Electronic equipment characterized in that corresponding electronic equipment is treated as a subunit. 8. A first electronic device capable of supporting a plurality of protocols on a bus capable of carrying a plurality of protocols, a second electronic device capable of supporting only a predetermined protocol among the plurality of protocols, A third electronic device capable of supporting only another predetermined protocol among a plurality of protocols is connected, and the second electronic device transmits a control command for the third electronic device to the first electronic device using the predetermined protocol. Transmitting a control command to the first electronic device, converting the received control command into the other predetermined protocol, and transmitting the control command to the third electronic device.