JP2002198970A - Data communication method and electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide effective usage of paths with the restricted channel number. SOLUTION: Data communication is conducted among devices connected with a path where control signals are transmitted by asynchronous communication packets and information signals by synchronous communication packets. A first device issues an output request for information signals to a second device by asynchronous communication packets, and the second device answers the channel information for information signals, which are being outputted, to the first device by asynchronous communication packets in response to the output request, and the first device inputs information signals by synchronous communication packets based on the channel information.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data communication method and an electronic apparatus connected by a bus for transmitting a control signal and an information signal in packets.

[0002]

2. Description of the Related Art Conventionally, for example, a video tape recorder (hereinafter, referred to as VTR), a television receiver (hereinafter, referred to as TV).
), Etc., via digital communication lines.
As a communication system for transmitting a V signal in a packet, D2
A communication system using B (Domestic Digital Bus) has been considered.

First, an example of such a communication system will be described with reference to FIG. This communication system has A
The V device includes a TV, a video camera (hereinafter, referred to as CAM), a VTR-A, and a VTR-B. Then, the output plug P3 of the CAM and the input plug P1 of the TV,
Between the output plug P3 of the VTR-A and the input plug P1 of the VTR-B, and between the output plug P3 of the TV and the input plug P1 of the VTR-A, AV signal lines L1, L2, and L3 that can transmit AV signals only in one direction. It is connected. Also, CA
M and VTR-A, VTR-A and VTR-B, TV and VT
R-A are connected by control signal lines (buses) D1, D2, D3 capable of transmitting control signals in both directions. Since each AV device has an input / output function of a control signal and an AV signal, for example, bidirectional transmission of a control signal between a CAM and a TV or a VTR-B is possible,
An AV signal can be transmitted to A or VTR-B.

FIG. 20 shows a main configuration of each AV device in the communication system shown in FIG. The input / output plugs of the AV signals of the respective AV devices are P1 and P1 so as to be directly exposed to the outside from a functional unit called a switch box (SWBox).
2, P3 only, and the other A
Connected to the input / output plug of the V device. In addition, other A
A control signal line is bus-connected to the V device separately from the AV signal line, and commands such as connection control are transmitted and received. Furthermore, each AV device has its own function unit,
For example, a VTR has a deck for recording and reproduction and a tuner for selecting a received signal, and a TV has a monitor and an amplifier. Although not shown, an AVC (AV controller) for controlling the operation of the entire AV device is provided. Hereinafter, in the present specification, these functional units are referred to as sub devices.

[0005] In the communication system configured as described above, two types of methods for performing control connection are considered. Hereinafter, these are referred to as connection control method 1 and connection control method 2, and will be described in order.

In connection control method 1, each user sets in advance the connection configuration information indicating which input / output and which direction the plug of each AV device is connected to which plug of which partner AV device for each plug. keeping. With this, when receiving the connection control command,
Connect the sub-device that is the source of the AV signal and the output plug that is expected to reach the destination, or connect the input plug of the designated number and an appropriate output plug to pass through the AV device as desired. At the same time, the command is propagated to the AV device connected to the end of the output plug. Then, the purpose is achieved when the command reaches the sub-device in the specific AV device designated as the destination.

At this time, since the command cannot be transmitted to the non-bus compatible AV device via the control signal line, the plug number of the AV device connected to the AV device is directly designated. For example, when a non-bus compatible AV device is connected to the plug P2 of the VTR device B in FIG.
This is performed by designating the plug P2 of the R device B.

Next, in connection control method 2, one central AV device (hereinafter referred to as AV center)
It manages all connection information indicating in which direction (In / Out) the port is connected to which port of what partner AV device for each plug of the device. Then, when a command for requesting an AV signal connection is received via the control signal line, the command is transmitted to a target AV device via the control signal line. The target AV device receives this command,
Performs input switching.

At this time, it is possible to specify a sub-device by category (BS tuner, Hi8 deck, etc.) in the first connection request from the command master. However, the plug designation at the time of the connection request is possible only for the plugs within the user who know the structure.

[0010]

In the connection control method 1, a control signal line is congested by sequentially transmitting a command to an adjacent AV device. In addition, depending on the settings of the intervening AV equipment, an infinite loop may occur. Furthermore, in order to directly specify the plug number, the command master needs to know the configuration of the AV device to be controlled and further, the connection configuration of the AV device of the entire system.

In connection control method 2, even if the connection is simple with the other party connected to the end of the plug,
This cannot be achieved without always asking the AV center. Also, at the time of connection request, it can be specified in the sub-device category, but the plug can be specified only for the plugs within the user who knows the structure.

Further, in either connection control method, if another AV device exists between the AV device that has made the connection request and the target AV device, it passes through all the existing AV devices. It is necessary to set the input / output of the AV signal. Therefore, as the number of AV devices constituting the system increases, A
The number of V devices increases, and control becomes complicated. Therefore, measures such as limiting the system configuration are required. Also, AV
Since the signal line can transmit a signal only when the power of the AV device is ON, it is necessary that the power of all the AV devices passing through is ON.

An object of the present invention is to provide a data communication method and an electronic device which can solve such a problem.

[0014]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a data communication between devices connected by a bus in which a control signal is an asynchronous communication packet and an information signal is a synchronous communication packet. In the method, a first device requests an output of an information signal to a second device in the asynchronous communication packet, and the second device responds to the output request to output a channel of the information signal. Information is returned to the first device in the asynchronous communication packet, and the first device inputs the information signal in the synchronous communication packet based on the channel information.

Further, the present invention is an electronic device for communicating data connected by a bus for transmitting a control signal in an asynchronous communication packet and transmitting an information signal in a synchronous communication packet. Requesting the output of an information signal with the asynchronous communication packet, and the other device responding to the output request with the channel information of the information signal being output in the asynchronous communication packet in response to the output request. The information signal is input in the synchronous communication packet based on the obtained channel information.

[0016]

According to the present invention, the first device requests the second device to output an information signal, and the second device responds to the request by returning the position of the output information signal. Then, the first device knows the position of the information signal from the response,
The input is switched so that the information signal of the position can be input.

Further, by outputting the information signal only when there is a device to which the information signal is being input, it is possible to prevent an unused information signal from flowing to the bus.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. [1] Communication system to which the present invention is applied [2] Concept of signal input switching [3] Specific example [4] Concept of signal input / output management [5] Details will be described in the order of specific examples.

[1] Communication System to which the Present Invention is Applied FIG. 1 is a system configuration diagram showing an example of the configuration of a communication system to which the present invention is applied. This communication system uses AV
The device includes a CAM1, a TV1, VTRs 1 to 4, and an editing machine (editing controller). And CAM
1 and TV1, TV1 and VTR3, VTR3 and VTR1 and editing machine, VTR1 and VTR2, and editing machine and VTR4
Are connected by a P1394 serial bus. P
The 1394 serial bus can transmit a control signal and an AV signal mixedly in two directions. Each device is P1
It has a function of relaying control signals and AV signals on the 394 serial bus.

FIG. 2 shows the AV in the communication system of FIG.
FIG. 2 is a block diagram illustrating a basic configuration of a VTR that is an example of a device. This VTR includes a deck sub-device 1 and a tuner sub-device 2, which are basic blocks as a VTR.
An operation unit 3 and a display unit 4, which are user interfaces;
In addition to the microcomputer 5 that controls the operation of the entire VTR, P1
A digital interface (hereinafter, referred to as a digital I / F) 6 for the 394 serial bus, a deck sub-device 1, a tuner sub-device 2, and a digital I / F
A switch box sub-device 7 for switching signals between F6 is provided. When the AV device is a TV, a monitor sub-device and an amplifier sub-device are provided instead of the deck sub-device 1, and when the AV device is a CAM, a camera sub-device is provided instead of the tuner sub-device 2.

As shown in FIG. 3, for example, the display unit 4 of each AV device is configured so that the names of all devices on the communication system are displayed on fluorescent tubes, and the keys 3a of the operation unit 3 are operated. Thereby, a partner for transmitting or receiving the AV signal can be selected. All devices on the communication system may be displayed simultaneously or sequentially. Alternatively, only devices other than the user may be displayed. Further, these operations may be performed using an infrared remote controller or a mouse. If the device is a TV, it can be displayed on the monitor sub-device. In addition, pictograms (icons) can be displayed instead of device names.

In the communication system shown in FIG. 1, communication is performed in a predetermined communication cycle (for example, 125 μs) as shown in FIG. In addition, it is possible to perform both synchronous communication for continuously communicating at a constant data rate like a digital video signal and asynchronous communication for transmitting a connection control command or the like irregularly as necessary.

At the beginning of the communication cycle, there is a cycle start packet CSP, followed by a period for transmitting a packet for synchronous communication. Channel numbers 1, 2, 3,... For each packet for synchronous communication
By attaching N, a plurality of synchronous communications can be performed. For example, if channel 1 is allocated to communication from CAM1 to VTR1, CAM
1 transmits a synchronous communication packet with a channel number 1 immediately after the cycle start packet CSP,
The communication is performed by monitoring the bus and taking in a synchronous communication packet with channel number 1. Furthermore, VT
If channel 2 is allocated to communication from R3 to VTR4, communication from CAM1 to VTR1 and VTR1
3 to the VTR 4 can be performed in parallel.

After the transmission of the synchronous communication packets of all the channels is completed, a period until the next cycle start packet CSP is used for asynchronous communication. Asynchronous communication packets (packets A and B in FIG. 4) have the physical and logical addresses of the transmitting device and the receiving device, and each node takes in the packet with its own address.

[2] Concept of Signal Input Switching FIG. 5 shows an example of a main configuration of an asynchronous communication packet used in a communication system to which the present invention is applied. In this figure, the master address is the logical address of the source of the packet, the slave address is the logical address of the destination, the frame type is the type of the packet (command, response, inquiry, etc.), and the SSSA / DADA is the subdevice address of the source or destination. , OPC (opcode) and OPR (operand) are the contents of the command.

Hereinafter, the CAM will be described with reference to FIG. 6 showing the input switching procedure and FIG. 7 showing the packets used in each procedure.
A description will be given of an example in which a reproduced image of No. 1 is recorded by the VTR 1.

First, the command master requests CAM1 to "output to CH?" (A1). On the other hand, CAM1 sends the command master (output OK.CH).
Output to 1. (A2). Next, in response to this, the command master requests the VTR 1 to input "CH1" (A3). Then, the VTR 1 answers "CH1 input OK." To the command master (A
4). Thus, the input switching process ends.

Here, the command master is an AV device which outputs a command first, and depends on whether the device has a function as a command master in advance and which AV device is used to select a communication partner. The master AV device changes (see a specific example described later). The SW BOX (switch box) in the SSDA / DSDA of the packet means that the purpose of the command is input / output switching. In addition, P139
The input switching command at 4 is tentatively called P1394 input switching. Further, Deck (deck) in the destination of the AV signal means a deck sub-device of CAM1.

[3] Specific Examples (1) When Recording a Playback Image of CAM1 with VTR1 and VTR2 As described above, the display units of VTR1 and VTR2 are arranged so that AV equipment on the communication system displays fluorescent tubes. With this configuration, the user can select the target CAM 1 as a communication partner (input partner) while viewing this. In this way, when the user sets VTR1 and VT
When the operation mode is set using R2, VTR1 and VTR2 become command masters. Hereinafter, the operation will be described with reference to FIG. 8 showing an input switching procedure and FIG. 9 showing an example of a packet structure of a command used in each of them.

First, the VTR 1 issues a message “CH?
Output to (B1). Next, in response to this, the CAM1 answers to the VTR1 "OK to output. Output to CH1." (B2). The VTR 1 inputs CH1 and starts recording.

Next, similarly to the processing of VTR1, VTR2
Requests CAM1 to "output to CH?" (B3). Next, in response to this, CAM1 replies to VTR2, "Output OK. Outputting to CH1." (B
4). The VTR 2 also inputs CH1 and starts recording.

Here, the description has been made on the assumption that the VTR 1 sends a command to the CAM 1 and then the VTR 2 sends a command to the CAM 1. However, these operations are actually performed independently.

(2) When a playback image of VTR 3 is recorded on VTR 4 using an editing machine In this case, VTR 3 is output using a display section of the editing machine.
VTR 4 is selected as the input AV device. In this case, the editing machine becomes the command master. Hereinafter, the input switching procedure will be described with reference to FIGS.

First, the editing machine, which is the command master,
Request VTR3 to "output to CH?" (C1). Next, in response to this, the VTR 3 outputs to CH2 because CH1 is already used, and replies to the editing machine that "output is OK. Output to CH2" (C2). Next, the editing machine requests the VTR 4 to input "CH2" (C3). On the other hand, VTR4 sends "CH
2 input OK. (C4). The VTR 4 inputs CH2 and starts recording.

[4] Concept of signal input / output management Hereinafter, referring to FIG. 12 showing input / output management procedures and FIG. 12 showing packets used in each procedure, a reproduced image of CAM1 is recorded on the VTR 1, and thereafter the VTR 1 A description will be given of an example in which recording is interrupted.

First, the command master requests CAM1 to "output to CH?" And further holds the address of CAM1 (D1). Here, as the address, not a node ID (physical address of device) peculiar to the P1394 serial bus, but an address for each product category (logical address of device) is used. The reason for this is that, for example, when dubbing between predetermined AV devices, if another AV device unrelated to the dubbing is removed from the system,
The bus is reset. At this time, the node ID after reset changes because the configuration of the system changes. However, since the address for each product category is held in the register of the AV device, the recording state can be protected.

Next, CAM1 responds to the command master (output OK, output to CH1) and adds 1 to the count value of the input device (D2). It is not necessary to hold the address of the command master that has requested output, but since there may be multiple input AV devices, it is difficult to hold all the addresses of devices that have requested output. Here, the command master holds information that CAM1 is outputting to CH1.

Next, in response to this, the command master requests the VTR 1 to input "CH1."
3). In this case as well, it is not necessary to hold the address, but since it is necessary to manage the number of partner devices that have requested inputting responsibly, the count value of the device that has requested input is increased by one. However, when an input is requested, it is considered to be a quasi-output device, and when an output is requested, it is considered to be an output device.
Input devices are counted both when an input request is made and when an output request is made, and both can be made with a common structure.

Next, the VTR 1 sets "C" as the command master.
H1 input OK. And the command master address is held (D4). Up to this point, the input / output setting is completed, and the VTR 1 starts recording the output of the CAM 1.

Next, a case where the VTR 1 stops recording after a while will be described. First, the VTR 1 informs the command master that "CH1 input has been interrupted." Then, the input is interrupted, and the held command master address is cleared (D5). Here, the Dummy (dummy) of the packet is the source C
It means the interruption of H1.

Next, in response to this, the command master returns "CH1 input interrupted OK" to the VTR 1 and decrements the counter number of the input device by 1 (D6). Therefore, the total of the counter becomes 0, and it can be determined that there is no input device.

Next, from the address information stored in D1 and D2, it is known that CAM1 is being output to CH1, so "CH1 input was interrupted."
Tell Also, since all the input devices that the user is counting no longer exist, the address is cleared (D
7).

On the other hand, CAM1 replies to the command master, "CH1 input interrupted OK.", And decrements the count value of the input device by one. Here, since the count value is 1, the current count value becomes 0, and it is determined that there is no input device, and the loading of the AV signal onto the bus is interrupted (D8).

If the device outputting the AV signal, not the input device itself, interrupts the signal output for some reason, the packet reading position (channel ) Can be determined not to include an AV signal, and in that case, the signal input is spontaneously interrupted.

FIG. 14 shows the correspondence between the command master and the slave devices (AV devices other than the command master) regarding the necessity of holding the address when switching the input / output of the signal.

As described above, according to the present invention, input / output management is performed so that unused information signals are prevented from being wasted on the bus and more AV signal processing can be performed within a limited number of channels. Things.

[5] Specific Example (1) A case where a reproduced image of CAM1 is recorded by VTR1 and VTR2, and input is interrupted in the order of VTR1 and VTR2. In this case, as in [3] (1), VT
R2 both become command masters. Hereinafter, the operation will be described with reference to FIG. 15 showing an input / output management procedure and FIG. 16 showing an example of a packet structure of a command used in each of them.

First, the VTR 1 sends “CH?
Output to ". At the same time, the address of CAM1 is held (E1). Next, on the other hand, CAM1
Respond to TR1 as "OK to output. Output to CH1." Increase the count value of the number of input devices by 1 (E2). Therefore, VTR1 inputs CH1 and starts recording. Here, VTR1 also holds information that CAM1 is outputting to CH1.

Next, similarly to the processing of VTR1, VTR2
Requests CAM1 to "output to CH?" And holds the address of CAM1 (E3). Next, in response to this, the CAM1 answers to the VTR2, "OK to output. Output to CH1.", And further increases the count value of the number of input devices by 1 (E4). As a result, the total number of input devices is two. Here, VTR2 also holds information that CAM1 is outputting to CH1.

After a while, the VTR 1 informs the CAM 1 holding the address at E 1 that “CH1 input has been interrupted.” And the CAM that was held
The address 1 and CH1 are cleared (E5). next,
In response to this, CAM1 replies to VTR1 "CH1 input interrupted OK." And decrements the count value of the input device by 1 (E6). Although the total number of input devices is reduced to 1, CAM1 sends A to CH1 because there is still one input device.
Continue outputting the V signal.

Next, the VTR 2 also informs the CAM 1 that has remembered the address at E4 that "CH1 input has been interrupted." Here, the address of CAM1 and CH1 are cleared (E7). Next, on the other hand, CAM1
Answer "CH1 input interrupted OK" to R2, and further reduce the count value of the input device by one. As a result, the counter number of the input device becomes 0, so that it is determined that all the input devices have run out, and the CAM1 suspends the flow of the AV signal to the bus (E8).

It is to be noted that CAM1 is used for some reason.
When the output of the signal is interrupted, VTR1 and VTR2
It is determined that the AV signal is not output to H1, and the input is interrupted by timeout processing.

(2) Using the editing machine, monitor the reproduced image of VTR3 on TV1 and record on VTR4, and then
When inputting is interrupted in the order of VTR4 and TV1 In this case, the editing machine becomes the command master as in the case of [3] (2). Therefore, VTR3 and VTR4, TV
Since it is known that data is exchanged between the devices 1, there is no need to select an input target device on a fluorescent tube display of a VTR or TV. Hereinafter, the procedure will be described with reference to FIGS.

First, the editing machine, which is the command master,
Request VTR3 to "output to CH?"
The address of the VTR 3 is held (F1). Next, in response to this, VTR3 uses CH1 because it has already been used.
Output to CH2, reply to the editing machine "OK to output. Output to CH2.", And increase the count value of the input device by one.
The editing machine also holds information that the VTR 3 is outputting to CH2 (F2).

Next, the editing machine requests the TV 1 to input "CH2", and increases the count value of the input requesting device by one (F3). On the other hand, TV1 sends "CH2
Input OK. And keep the address of the editor (F
4). Next, the editing machine requests the VTR 4 to input "CH2", and further increases the count value of the input requesting device by one (F5). Thus, the total number of input devices managed by the editing machine is two. The VTR 4 responds to the editing machine with "CH2 input OK." And holds the address of the editing machine (F6).

After that, the VTR 4 informs the editing machine, which has memorized the address in F6, that "the input of CH2 has been interrupted." And clears the address of the editing machine (F7). In response to this, the editing machine sends “CH2 input interrupted O to VTR4”.
K. And decrement the count value of the device for which input has been requested by one. Accordingly, the total number of input-requested devices managed by the editing machine is one. Since there is still one input device, the address of VTR 3 is held as it is (F
8).

Next, the TV 1 informs the editor that "CH2 input has been interrupted." (F9). The editing machine decrements the count value of the device for which input has been requested by one, and the total becomes 0. Therefore, it is determined that all the input devices managed by the editing machine no longer exist, and the TV 1 answers "CH2 input interrupted OK." ) To the VTR 3 holding the address with "C
H2 input was interrupted. And the address and CH2
Is cleared (F11). On the other hand, the VTR 3 answers the editing machine with “CH2 input interrupted OK.” And reduces the count value of the input device counted by the VTR 3 by one. As a result, the total of the count values becomes 0, and it can be determined that all the input devices are gone.
2 is interrupted (F12).

It is to be noted that the VTR 3 is set to C for some reason.
When the output to H2 is interrupted, the VTR 4 can determine that the AV signal is not output on CH2.
Interrupt input by timeout processing.

Also, for example, even when the VTR 3 itself starts outputting and requests the TV 1 to input "CH2", and the VTR 4 requests the VTR 3 to "output", in either case, Since the meaning of the count is the same, the count value of the input devices managed by the VTR 3 becomes 2 in total, and it is determined that all the input devices are gone when both the TV 1 and the VTR 4 are notified that “CH2 input has been interrupted.” , VTR3 interrupt the output of the AV signal to CH2.

Although the P1394 serial bus is used here, other buses may be used as long as the digital bus can carry control lines and signal lines in a mixed manner. In addition, the selection of the input target device is not limited to the fluorescent tube display, and may be displayed by an OSD display such as a TV. Further, the present invention can be applied not only to a system connected to AV equipment but also to a system connected to a computer for data communication.

[0061]

As described above in detail, according to the present invention, an output device outputs a packet carrying an information signal to an arbitrary position (channel), and an input device outputs a packet to this output device. Since it is inquired whether or not the information has been output to the position, the information is input so that the device that wants to input the information signal can read the position of the packet transmitting the information signal, regardless of the route information between the devices existing in the communication system and the number of devices. Only the switching procedure is required, and the input / output management of the information signal is performed so that the information signal is output as a packet only when there is a device that is inputting the information signal. You don't have to flush the bus. Therefore, the bus can be effectively used within the limited number of channels.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram showing an example of a configuration of a communication system to which the present invention has been applied.

FIG. 2 is a block diagram showing a basic configuration of a VTR as an example of an AV device in the communication system of FIG.

FIG. 3 is a diagram illustrating an example of a display unit of an AV device in the communication system of FIG. 1;

FIG. 4 is a diagram illustrating an example of a communication cycle in a P1394 serial bus.

FIG. 5 is a diagram showing an example of a main configuration of an asynchronous communication packet used in a communication system to which the present invention is applied.

FIG. 6 is a diagram showing an input switching procedure when a reproduced image of CAM1 is recorded by VTR1.

FIG. 7 is a diagram showing a configuration of a packet used in the procedure of FIG. 6;

FIG. 8 is a diagram showing an input switching procedure when recording the output of CAM1 with VTR1 and VTR2.

FIG. 9 is a diagram showing a configuration of a packet used in the procedure of FIG. 8;

FIG. 10 shows the output of VTR3 using an editing machine to VTR4.
FIG. 6 is a diagram showing an input switching procedure when recording is performed by using the.

FIG. 11 is a diagram showing a configuration of a packet used in the procedure of FIG. 10;

FIG. 12 is a diagram showing an input / output management procedure when a reproduced image of CAM1 is recorded by VTR1.

FIG. 13 is a diagram showing an example of a packet structure used in the procedure of FIG.

FIG. 14 is a diagram showing a correspondence relationship regarding presence / absence of address holding during signal input / output with a command master and a slave device.

FIG. 15 is a diagram showing an input / output management procedure when a playback image of CAM1 is recorded by VTR1 and VTR2, and then input is interrupted by VTR1 and VTR2.

FIG. 16 is a diagram showing an example of the structure of a packet used in the procedure of FIG.

FIG. 17 shows a VTR 3 playback image using an editing machine.
4 is a diagram showing an input / output management procedure when the VTR 4 interrupts input after recording at 4.

FIG. 18 is a diagram showing an example of a packet structure used in the procedure of FIG.

FIG. 19 is a diagram showing an example of a configuration of a communication system in which conventional AV devices are connected by a digital communication line and an AV signal is transmitted in packets.

20 is a diagram illustrating a main configuration of each AV device in the communication system of FIG. 19;

[Explanation of symbols]

VTR1 to 4 Video tape recorder, TV1 television receiver, CAM video camera, 1 deck subdevice, 2 tuner subdevice, 3
Operation unit, 4 display unit, 5 microcomputer, 6 digital I / F, 7 switch box sub device

Continued on the front page (72) Inventor Makoto Sato 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo F-term in Sony Corporation (reference) 5C056 FA01 HA01 HA04 5K033 AA01 BA15 CB01 CB15 CC02 DA16 5K034 AA02 AA14 EE11 HH01 HH02

Claims (2)

[Claims] In a data communication method between devices connected by a bus for transmitting a control signal as an asynchronous communication packet and an information signal as a synchronous communication packet, a first device transmits information to a second device. A signal output request is made in the asynchronous communication packet, and the second device responds to the first device in the asynchronous communication packet with the channel information of the information signal being output in response to the output request. A data communication method, wherein the first device inputs the information signal in the synchronous communication packet based on the channel information. 2. An electronic device for communicating data connected by a bus for transmitting a control signal as an asynchronous communication packet and transmitting an information signal as a synchronous communication packet. Performed in an asynchronous communication packet, the other device responds to the output request in response to the output information signal channel information in the asynchronous communication packet, and based on the returned channel information, An electronic device, wherein an information signal is input in the synchronous communication packet.