JPH10124454A - Electronic equipment and its internal signal connection control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the exchange frequency between the commands and their responses when the connection of internal signals of an equipment is controlled by an external equipment by means of a connection control command of high flexibility in a system where the communication is performed among plural equipments which are connected together via a bus that can transmit both information and control signals. SOLUTION: A tuner subunit 12 contains the subunit output plugs 16 and 17, and a digital VCR(video cassette recorder) subunit 13 contains a subunit input plug 18 and a subunit output plug 19. When the connection of internal signals of a tuner unit 1 is controlled by an external equipment, the external equipment inquiries of all plugs 16 to 19 of the unit 1 including a subunit plug about the signal formats that can be handled by the plugs 16 to 19. Then the external equipment performs the connection of internal signals of the unit 1 after checking the connectable plugs.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to, for example, IEEE 1
A 394 serial bus (hereinafter referred to as a 1394 serial bus) connects a plurality of electronic devices, and performs a communication of information signals and control signals between these electronic devices.
More specifically, the present invention relates to a control method for enabling a signal connection inside an electronic device from an external electronic device.

[0002]

2. Description of the Related Art Digital video cassette recorders (hereinafter referred to as DVCRs), digital tuners, personal computers and other electronic devices (hereinafter simply referred to as devices) are referred to as 13 devices.
A system has been conceived, which is connected by a 94 serial bus and transmits and receives information signals such as digital video signals and digital audio signals and control signals such as operation control commands and connection control commands of the devices between the devices.

In such a system, in order to create a path for an information signal in an AV device such as a DVCR, an external terminal including a function block (subunit) serving as a source of the information signal or a 1394 serial bus, and an information terminal are connected. A model has been considered in which a signal stream connection is established between a functional block serving as a signal destination or an external terminal.

[0004] AV / C (Audio Video / C) is used as a device control command set on the 1394 serial bus.
control) command set. This command set defines a control command (CONNECT command: connection control command) for establishing a connection inside the AV device. This connection control command has two types of models. Optimized method for handling audio / video signals (CONNECT c
omand for audio / video st
stream: connection control command for audio / video stream) and a method (CONN) that can be used universally without limiting the type of signal to audio / video
ECT command for unspecifi
ed stream: connection control command for an unspecified signal stream).

As illustrated in FIG. 12, in a connection control command model for an audio / video stream, a device (unit) has a subunit for each function. The unit has a number of serial bus plugs that can be input and output simultaneously to the 1394 serial bus, and external plugs such as analog input and output. In the connection model of the connection control command for the audio / video stream, the connection is represented by indicating the source and the destination for each of the audio stream and the video stream. The inquiry command asks, for example, what is the source of the video signal coming to the analog video output terminal, and replies that the source is a VCR subunit.

[0006]

If only audio / video signals are handled as information signals as in conventional AV equipment, connection of signals in the equipment is performed using a connection control command method for audio / video streams. Control can be performed. However, when handling data other than audio / video signals, such as a data port of a digital broadcast tuner (set-top box), or when handling multiple systems of audio / video signals, connection control for audio / video streams is performed. Cannot be processed by command.

Therefore, it is conceivable to use a connection control command for an unspecified signal stream as a highly versatile connection control command. FIG. 13 shows an example of the model. Here, the concept of a plug is also introduced into the subunit. Then, an internal connection is established by connecting the plugs of the subunits.

However, merely providing plugs in the subunits does not make it clear which plug should be used to establish a connection within the device for performing desired signal processing. Therefore, in order to establish a connection, a connection control command is issued in all conceivable patterns of a combination of a source and a destination, and if a connection is established, the connection is accepted (Accept).
t) If it is not possible, there is no other way but to look at the response of rejection (Reject), and the number of times of exchanging commands and responses increases.

The present invention has been made in view of the above problems, and has been made in consideration of the communication of information signals and control signals between a plurality of devices connected by a bus capable of transmitting information signals and control signals. It is an object of the present invention to reduce the exchange of commands and responses when a signal connection inside a device is controlled from an external device using a highly versatile connection control command.

[0010]

SUMMARY OF THE INVENTION According to the present invention, there is provided a system for communicating information signals and control signals between a plurality of devices connected by a bus capable of transmitting information signals and control signals. A signal format that can be handled by all plugs of the device including the sub unit plug when sub-unit plugs are provided in each internal function block and the internal signal connection of the device is controlled from other devices connected by the bus Is controlled by a device that controls the device, checks the plugs that can be connected, and then performs signal connection inside the device that is controlled.

There are two methods for checking which signal format each plug corresponds to. One is to define the input plug signal format command and the output plug signal format command, which are currently defined as unit commands, as subunit commands, and to specify the signal format of the subunit plug by a control command. And the same status command is used to inquire about the signal format supported by the current subunit plug.

Another method is that the subunit has information on its own plug as a descriptor, which is a kind of register. When the signal format is switched from another device, writing is performed on the descriptor, and when it is desired to know the corresponding signal format, the descriptor is read.

[0013] Before issuing a command instructing to establish an internal connection of a partner device to be controlled, the device on the control side checks the signal format supported by the plug of the partner device. Can be. That is, the controlling device can establish a connection after checking the configuration of the other device.

[0014]

FIG. 1 is a block diagram showing the configuration of a tuner unit to which the present invention is applied. The tuner unit 1 includes a digital broadcast tuner block 2
And an analog terrestrial tuner block 3. The output of the digital broadcast tuner block 2 is connected to a VCR block 5 via a switch SW1, and is isochronous (hereinafter referred to as Iso) via a switch SW2.
It is connected to the signal processing block 8. The output of the analog terrestrial tuner block 3 is connected to the VCR block 5 via the A / D converter 4 and the switch SW1, and is output via the A / D converter 4 and the switch SW2.
o It is connected to the signal processing block 8. The tuner unit 1 has an analog input terminal 6. An A / D conversion and signal processing block 7 is connected to the analog input terminal 6. The output of the A / D conversion and signal processing block 7 is connected to the VC via the switch SW1.
R is connected to the R block 5 and Is
o It is connected to the signal processing block 8. Also, VCR
The output of the block 5 is connected to the Iso signal processing block 8 via the switch SW2. The Iso signal processing block 8 is connected to a 1394 interface (hereinafter, interface is referred to as I / F) block 9 and
The I / F block 9 is connected to an asynchronous (hereinafter referred to as Async) signal processing / control block 10 together with the Iso signal processing block 8. The Async signal processing / control block 10 controls switching of the switches SW1 and SW2. 139 I / F block 9 is 139
4 is connected to the serial bus, and communicates an Iso signal and an Async signal with another device (monitor unit or the like: not shown) connected to the 1394 serial bus.

Next, the operation of the tuner unit shown in FIG. 1 will be described. Here, 13
It is assumed that an analog video signal output from the analog input terminal 6 is digitized, subjected to data compression, and recorded in the VCR block 5 while being output to the 94 serial bus 11.

The antenna input from the satellite broadcast antenna is input to a digital broadcast tuner block 2 where the data stream of one or more desired programs is separated. Then, the separated data stream is transmitted to the switch S
It is sent to the Iso signal processing block 8 through W2. In addition, the switching control of the switch SW2 is performed, for example, when the user inputs from the operation unit such as the monitor television that the digital broadcast is received and displayed on the monitor television.
This is detected by a microcomputer such as a monitor television (hereinafter referred to as a microcomputer), and the 1394 serial bus 11
To the Async signal processing / control block 10 in the tuner unit 1 via the control unit.

The Iso signal processing block 8 includes a switch SW
2 is packetized and sent to the 1394 serial bus 11 via the 1394 I / F block 9. The packet transmitted to the 1394 serial bus 11 is input to a monitor unit or the like connected to the bus and displayed on the screen.

The analog video signal input from the analog input terminal 6 is subjected to digitization and data compression processing by an A / D conversion and signal processing block 7 and input to the VCR block 5 through the switch SW1 for recording. Is done. The switching control of the switch SW1 can be performed in the same manner as the switching control of the switch SW2.

FIG. 2 describes FIG. 1 using the concept of a logical plug according to the present invention. Here, the same parts as those in FIG. 1 are given the same numbers as those in FIG. The tuner subunit 12 is a logical block including both the digital broadcast tuner block 2 and the analog terrestrial tuner block 3 in FIG. The VCR subunit 13 is a logical block corresponding to the VCR block 5 in FIG. The external input plug 14 is a logical input plug corresponding to the analog input terminal 6 in FIG. The serial bus output plug 15 is Is
This is a logical output plug indicating an outlet from which the o signal is sent to the 1394 serial bus 11. This serial bus output plug is used for connection management (Connection Management) in the AV protocol of the 1394 serial bus.
nt) corresponding to the PCR (plug control register) defined in the protocol. The subunit output plug 16 is a logical output plug indicating an outlet from which the digital broadcast tuner block 2 of FIG. 1 outputs a data stream. The sub-unit output plug 17 is a logical output plug indicating an outlet for outputting an analog broadcast video signal received by the analog terrestrial tuner block 3 in FIG. The subunit input plug 18 is connected to the VC of FIG.
This is a logical input plug indicating the entrance of the digital video signal input to the R block 5. The subunit output plug 19 is a logical output plug indicating the exit of the digital video signal output from the VCR block 5 in FIG.

In FIG. 2, since the subunit output plug 16 of the tuner subunit 12 and the serial bus output plug 15 of the tuner unit 1 are connected, the tuner subunit 12 outputs a data stream from the subunit output plug 16. This indicates that the signal is output from the serial bus output plug 15 to the external 1394 serial bus. Further, since the external input plug of the tuner unit 1 and the subunit input plug 18 of the VCR subunit 13 are connected, the analog video signal input from the external input plug 14 is digitized, compressed, and compressed. 13 is input. Further, the subunit output plug 17 of the tuner subunit 12
Is not connected anywhere, indicating that the tuner subunit 12 is not outputting an analog video signal. Similarly, since the subunit output plug 19 of the VCR subunit 13 is not connected anywhere, it indicates that the VCR subunit 13 is not outputting a video signal.

Next, a procedure in which a device connected by a 1394 serial bus establishes a connection in another device using the concept of the logical plug described above will be described. The connection control command for the unspecified signal stream according to the present invention includes a connection management (Connection Ma) in the AV protocol of the 1394 serial bus.
PCR defined in the protocol)
(Serial bus plug corresponding to (Plug control register), external plug such as analog input / output terminal and optical digital audio terminal, and plug of sub unit.
Commands for specifying or inquiring each signal format are provided.

FIG. 3 is a flowchart showing the entire procedure, and FIGS. 4 to 9 show the formats of commands and responses used in the procedure.

First, as shown in step S1 of FIG. 3, the number of plugs in the unit is checked. FIG. 4A shows a command used in this step, and FIG. 4B shows a response to the command. “0” h of CTS (command transaction set) at the beginning of the command and response means that the command is an AV / C command set conforming to the 1394 serial bus protocol. CT /
RC (command type / response code) indicates the type of request in a command, and indicates the type of reply in a response. HA (header address) indicates a destination in the case of a command, and indicates a source in the case of a response. And
Commands and their parameters are indicated by OPC (operation code) and OPR (operand).

For example, the tuner unit 1 shown in FIG.
When a monitor unit (not shown) connected to the 94 serial bus 11 checks the number of plugs in the tuner unit 1, the monitor unit transmits a command in the format shown in FIG. The tuner unit 1 returns a response in the format shown in FIG. 4B to the monitor unit. At this time, the HA in FIG. 4A is a tuner unit. The OPC indicates that this command is a command for inquiring plug information.
F "h indicates that the number of serial bus input plugs, serial bus output plugs, external input plugs, and external output plugs has been inquired. When the tuner unit 1 receives this command, the tuner unit 1 receives OPR1 to OPR4.
And send the response to the monitor unit with the number of each plug. The monitor unit can know the number of various plugs of the tuner unit 1 by receiving the response.

Next, as shown in step S2 of FIG. 3, the format of a signal that can be handled for each plug of the unit is checked. FIG. 5 shows the format of the command and response used in this procedure. Here, FIG. 5A shows a command for inquiring the signal format of the input plug.
FIG. 5B shows a response to the command.
FIG. 5C shows a command for inquiring the signal format of the output plug, and FIG. 5D shows a response to the command. The plug for inquiring the signal format is individually designated by OPR0 of each command and response. The fmt of the OPR1 of the response indicates, for example, a DVCR format or an MPEG format, and the fdf of the OPR2 to 4 indicates, for example, a 525/60 system or a 1125/60 system.

Next, as shown in step S3 of FIG. 3, the type and number of subunits in the unit are checked. FIG.
FIG. 6A shows a command used in this step.
(B) is a response to the command. OP
“Subunit information” in C indicates that this command and response are related to the inquiry and reply of the subunit information. The "page" of OPR0
Indicates the number when this command and response are exchanged multiple times.

Next, as shown in step S4 of FIG. 3, the number of plugs is checked for each subunit in the unit. FIG.
FIG. 7A shows a command used in this step.
(B) is a response to the command. In this command and response, the HA is a subunit to be checked for a plug. That is, for example, FIG.
When checking the plug of the tuner subunit 12, the HA is set to the tuner subunit. The destination plug and the source plug in the OPR1 and OPR2 of the response correspond to the input plug and the output plug of the subunit, respectively, but the "input plug" and the "output plug" are used for the plug of the unit. Therefore, they are distinguished by calling them destination plugs and source plugs. Tuner unit 1
Receives the command shown in FIG. 7A,
The number of destination plugs and source plugs are entered in OPR1 and OPR2 of the response (b) and sent to the monitor unit. The monitor unit can know the number of plugs for each subunit in the tuner unit 1 by receiving the response.

Next, as shown in step S5 of FIG. 3, the format of a signal that can be handled for each plug of the subunit is checked. FIG. 8 shows the format of the command and response used in this procedure. Here, FIG. 8A shows a command for inquiring the signal format of the input plug, and FIG. 8B shows a response to the command. FIG. 8C shows a command for inquiring the signal format of the output plug, and FIG. 8D shows a response to the command. The plug for inquiring the signal format is individually designated by OPR0 of each command and response. The format of the command and response is the same as the command and response shown in FIG. 5 for checking the format of a signal that can be handled for each plug of the unit, except that the HA is a subunit. Therefore, for example, the monitor unit sends a command shown in FIG. 8A to the tuner subunit 12 in the tuner unit 1 and receives a response shown in FIG. You can know the format of the signal that can be handled. Similarly, by sending the command shown in FIG. 8C and receiving the response shown in FIG.
The format of a signal that can be handled for each output plug of the tuner subunit 12 can be known.

According to the above-described procedures of steps S1 to S5, the number of plugs for each unit to be connected and the signal format that can be handled for each plug are known, and the number of subunits for each unit and the number of subunits for each subunit are known. When the number of plugs and the signal format that can be handled for each plug are known, a connection in the unit is established as shown in step S6 in FIG. FIG. 9 shows commands and responses used in this procedure. FIG.
The command (a) instructs to establish a connection inside the unit from the source plug of the subunit specified by OPR1 to OPR2 to the destination plug of the subunit specified by OPR3 to OPR4. Here, for example, when instructing to establish a connection from the subunit to the serial bus output plug, OP
The serial bus output plug and its number are designated by R3 to R4. When the plug of the subunit supports a plurality of signal formats, the format can be switched by designating the signal format of the subunit with a control command.

FIGS. 10 and 11 illustrate a method of checking a signal format supported by a plug by a procedure different from that of FIG. Each device has plug information of each subunit as shown in FIG. 10 in a register called a descriptor. Since various information is written in the descriptor, the type is specified by the data ID. FIG. 10A shows that plug information of a subunit is specified by a data ID of “xx”. It has a 16-bit address space table for each data ID. FIG. 10B shows that the information of the source plug # 0 is written at the address “0000h”, for example.

To establish a connection from an external device, a command shown in FIG. 11A is sent. The OPC of this command means a command for instructing reading of the descriptor. OPR0 and OPR
The data ID and address shown in FIG. The subunit of the device that receives this command
The information of the plug specified by the data ID and the address is read, put into OPR4 of the response, and sent back to the external device. External devices receive this response,
The signal format corresponding to each plug of the subunit can be known.

If the external device wants to switch the signal format of the subunit plug of the device to which a connection is to be made internally, it sends a command shown in FIG. 11C. The OPC of this command means a command for instructing the descriptor to write. The subunit of the device receiving this command rewrites the information of the plug specified by the data ID and the address,
A response indicating that rewriting has been accepted is sent back to the external device.

[0033]

As described above in detail, according to the present invention, communication of information signals and control signals is performed between a plurality of devices connected by a bus capable of transmitting information signals and control signals. In a system, when a signal connection inside a device is controlled from an external device using a highly versatile connection control command, the exchange of commands and responses can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a tuner unit to which the present invention is applied.

FIG. 2 is a diagram describing FIG. 1 using the concept of a logical plug according to the present invention.

FIG. 3 is a flowchart showing a procedure in which a device connected by a 1394 serial bus establishes a connection in another device.

FIG. 4 is a diagram showing a format of a command and a response used in a procedure for checking the number of plugs of a unit.

FIG. 5 is a diagram showing command and response formats used in a procedure for checking a signal format that can be handled for each plug of the unit.

FIG. 6 is a diagram showing a format of a command and a response used in a procedure for checking the type and number of subunits in a unit.

FIG. 7 is a diagram showing a format of a command and a response used in a procedure for checking the number of plugs for each subunit in the unit.

FIG. 8 is a diagram showing command and response formats used in a procedure for checking a signal format that can be handled for each plug of a subunit.

FIG. 9 is a diagram showing a format of a command and a response used in a procedure for establishing a connection in the unit.

FIG. 10 is a diagram illustrating an example of information written in a descriptor.

FIG. 11 is a diagram showing a format of a command and a response used for writing / reading of a descriptor.

FIG. 12 is a diagram illustrating an example of a model of a connection control command for an audio / video stream.

FIG. 13 is a diagram illustrating an example of a model of a connection control command for an unspecified signal stream.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Tuner unit, 12 ... Tuner subunit, 13 ... VCR subunit, 14 ... External input plug, 15 ... Serial bus output plug, 16, 17, 19
... Subunit output plug, 18 ... Subunit input plug

Claims (6)

[Claims] 1. A system for communicating an information signal and a control signal between a plurality of electronic devices connected by a bus capable of transmitting an information signal and a control signal, wherein the electronic device has internal functional blocks. When a signal connection inside the electronic device is controlled from another electronic device connected by the bus, all plugs of the electronic device including the sub unit plug can be handled there. A signal connection control method inside an electronic device, wherein an electronic device that controls a signal format makes an inquiry, checks a connectable plug, and then makes a signal connection inside the electronic device that is controlled. 2. The electronic device on the controlling side checks a plug that can be connected by inquiring by a status command about a signal format that can be handled by a subunit plug inside the electronic device on the controlled side. Signal connection control method inside an electronic device. 3. The electronic device on the controlling side switches a signal format corresponding to the sub-unit plug by designating a signal format of a sub-unit plug inside the electronic device on the controlled side by a control command. 2. The signal connection control method according to claim 1, further comprising the step of: 4. A signal format which can be handled by the electronic device on the controlling side by reading storage means for information on the sub-unit plug provided inside the electronic device on the controlled side. The signal connection control method according to claim 1, wherein the signal connection control is performed. 5. The electronic device on the controlling side writes the information on the information on the sub-unit plug provided inside the electronic device on the controlled side, so that the sub-unit plug corresponds to the sub-unit plug. 2. The signal connection control method according to claim 1, wherein a format of a signal to be set is set. 6. An electronic device in a system for communicating information signals and control signals among a plurality of electronic devices connected by a bus capable of transmitting information signals and control signals, wherein each of the internal functions The block includes a sub-unit plug, and when a command for inquiring a format of a signal that can be handled by the sub-unit plug or a command for setting a corresponding signal format is received from another electronic device connected by the bus, the signal that can be handled is An electronic apparatus, comprising: means for setting a format response or a corresponding signal format.