KR100677069B1 - Connection management method between devices connected by digital interface and command structure therefor - Google Patents

Abstract

Disclosed are a method for managing a connection between devices connected through a digital interface and a command structure therefor. The present invention is connected to a predetermined digital interface, and a device for transmitting information through a predetermined data transmission standard and the device receiving the information to inform the other device when the state change of the connection occurs after a predetermined connection is established In addition, the real-time information is transmitted between devices connected through a digital interface, such as a variety of state changes in the connection of the information transmission flow to allow the other device to cope with this, and manage the connection state more efficiently.

Description

Connection management method between devices connected by digital interface and command structure therefor}

1 is a schematic diagram illustrating a network system connected by a general IEEE 1394 bus.

FIG. 2 is a diagram illustrating the format of an output plug control register (oPCR) shown in FIG. 1.

FIG. 3 is a diagram illustrating a format of an input plug control register iPCR shown in FIG. 1.

4 is a diagram illustrating a connection management command structure according to the present invention.

5 is a flowchart according to an embodiment of a connection management method according to the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of information transmission control, and more particularly, to a connection management method capable of informing a counterpart device and a user of a change in connection management state between devices connected through a digital interface and a command structure therefor.

Home or industrial equipment is transmitting and receiving real-time information in a state where they are connected to each other by a bus of a predetermined digital interface standard, for example, the Institute of Electrical and Electronics Engineers, Inc. (IEEE) 1394 standard. In other words, when devices such as digital televisions (DTVs), digital video camcorders, and set-top boxes (STBs) are connected to each other in an IEEE 1394 home to form a network, video and audio information between the devices Real-time information such as this is being transmitted.

In FIG. 1 schematically illustrating a network system connected by a general IEEE 1394 bus, real-time information is output from a virtual output plug of one device and input to an input plug of another device, and such a connection. (connection) is conceptual and does not actually make a physical connection.

A source device (here STB) 100 having an output plug 101 and transmitting information includes an output plug control register for controlling the flow of information output through the output plug 101. oPCR, 111, likewise a sink device (in this case DTV, 200) having an input plug 201 and receiving information, input plug control for controlling the flow of information input to the input plug 201 There is an input plug control register (iPCR, 211). The control device having the controller 300 may be one of the STB 100 or the DTV 200, or may be another third device, and the control values of the oPCR 111 and the iPCR 211. It controls the connection and establishes or breaks the connection so that information is transmitted.

Therefore, real-time information is transmitted from the output plug 101 to the input plug 201, in which the related control information is written in the oPCR 111 and iPCR 211 corresponding to each plug, and the oPCR ( The flow of real-time information is controlled by reading the values written in 111 and iPCR 211 or by writing control values therein.

Here, the control values written in the oPCR 111 and the iPCR 211 will be described with reference to FIGS. 2 and 3.

First, the definition according to the format of the 32-bit oPCR 111 shown in FIG. 2 is as follows, and the numbers indicate allocated bits. On-line indicates whether the corresponding output plug is online (value of "1") or offline (value of "0"). The broadcast connection cournter indicates whether a broadcast-out connection is present (value of "1") or not (value of "0") in the output plug. The point-to-point connection counter represents the number of point-to-point connections present in the output plug. The channel number represents the channel number that the output plug can use to transmit isochronous data flow when the output plug is activated. The data rate indicates the transmission rate (or bitrate) that the output plug uses to transmit isochronous packets of isochronous data flow when the output plug is valid. The overhead ID indicates the bandwidth required in addition to the bandwidth required for transmitting the payload of the isochronous packet. Payload indicates the maximum data size of isochronous data that the output plug will output when the output plug is valid.

The definition according to the format of the 32-bit iPCR 211 shown in FIG. 3 is as follows, and the number represents the assigned bit. The on-line bit indicates whether the corresponding input plug is online (value of "1") or offline (value of "0"). The broadcast connection cournter indicates whether there is a broadcast-in connection at the input plug (value of "1") or not (value of "0"). The point-to-point connection counter indicates the number of point-to-point connections present in the input plug. The channel number represents the channel number that the input plug uses to receive isochronous data flow.

Therefore, the control device having the controller allocates the channel value allocated to the oPCR 111 and the iPCR 211 to which the connection is established by assigning the channel value to be used and writes the channel value shown in FIGS. 2 and 3. If other control values (online bit value, connection counter value ...) are written to the oPCR 111 and iPCR 211, the source device and the sink device transmit or stop information according to this value.

As shown in FIGS. 2 and 3, there are two types of connection to which information is transmitted, a point-to-point (p2p) connection and a broadcast connection. In the case of a p2p connection, only the control device that establishes the connection is terminated. break) Thus, when a third control device establishes a p2p connection, the two configured devices (the source device and the sink device) must continue to send even if they do not want to send any more information and receive it no longer.

To tell you this, define a new control command in the AV / C audio-video / control command transaction sets (CTS) to notify the controlling device or connected device when it no longer wants to send or receive information. An algorithm is proposed to make this possible.

That is, it defines a command that informs when a change occurs in a device that transmits or receives real-time information, and whether each input plug wants to accept input and whether each output plug wants to output. It can also inform you if the format of the signal output from the output plug has changed.

However, there was a problem using this defined command that other factors that control the flow of information, such as changes in bandwidth and changes in information about how many devices are connected to the connection, are not known.

In order to solve the above problems, an object of the present invention is to change a variety of connection state (data transmission and reception status, data processing availability, data bandwidth) of the information transmission flow during the real-time information transmission between devices connected via a digital interface It is to provide a connection management method that informs.

Another object of the present invention is to provide a connection management command structure that can inform various state changes regarding the flow of information transmission while real-time information is transmitted between two devices connected by a digital interface.

In order to achieve the above object, the connection management method according to the present invention is connected to a predetermined digital interface, and after a predetermined connection is established between a device for transmitting information and a device receiving information through a predetermined data transmission standard. It is characterized by including the step of notifying other devices when the state change of the connection occurs.

In order to achieve the above object, the connection management command structure according to the present invention is connected to a predetermined digital interface, and a device for transmitting information and a device receiving information through a predetermined data transmission standard have a predetermined connection. The connection management command for informing another device of a change in the state of a connection after the connection has been established has a connection register type indicating whether it is an input plug control register or an output plug control register and identification information of the corresponding plug to which the connection is set. .

Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of the connection management method between the devices connected by the digital interface according to the present invention and a command structure therefor.

The present invention is an output plug control register defined in the IEC 61883 standard (Specification of Digital Interface for Electronic Audio / Video Equipment, Part 1, December 1995, HD Digital VCR Conference), which is a data transmission standard between devices using the IEEE 1394 standard. A connection management command structure for informing the control device or the connected counterpart device when a change in the control value of the (oPCR) and the input plug control register (iPCR) occurs as shown in FIG. 4 is defined in the AV / C CTS standard. Observe the command format defined in.

In FIG. 4, an opcode name is defined as connection management, and operand [operand [0]) is 1 byte. Looking at the contents of the field of the byte, msb (most significant bit) indicates whether it is iPCR or oPCR. One bit of the connection register type (I / O) and the lower six bits contain plug identification information indicating the number of the corresponding plug to which the connection is set, and the upper one bit is reserved.

operand[4])을 추가함으로써 커넥션 관리에 관한 여러가지 인자들을 전송할 수 있다. 즉, 도 2에 도시된 oPCR의 포맷에 따라 비트 필드(온라인, 브로드캐스트 커넥션 카운터, 포인트대포인트 커넥션 카운터, 채널 번호, 데이터 레이트, 오버헤드 ID, 패이로드) 중에서 일부분만 지정하고, 도 3에 도시된 iPCR의 포맷에 따라 비트 필드(온라인, 브로드캐스트 커넥션 카운터, 포인트대포인트 커넥션 카운터, 채널 번호) 중에서 일부분만 지정하여 불필요한 응답의 전송을 막을 수 있다.other operands after operand [0]

By adding operand [4]), you can send various parameters related to connection management. That is, only a part of the bit fields (online, broadcast connection counter, point-to-point connection counter, channel number, data rate, overhead ID, payload) according to the format of the oPCR shown in FIG. According to the illustrated format of the iPCR, only a part of the bit fields (online, broadcast connection counter, point-to-point connection counter, and channel number) can be designated to prevent unnecessary response transmission.

operand[4])를 이용하여 해당 비트 필드의 위치의 비트들의 제어값을 설정하여 커넥션 관리 명령을 전송한다. 예를 들어, 온라인 비트 필드에만 관심이 있다고 하면 그 비트만 지정하도록 오퍼랜드에 지정할 수 있다. 즉, 온 라인에 해당하는 비트 위치가 b0이라면 오퍼랜드(operand[1])에서 비트 b0에 해당되는 위치만 "1"로 하고, 나머지 비트들은 모두 "0"으로 하여 전송할 수 있다. Thus, when one wants to know the change in the desired bit field with respect to 32 bits of oPCR or iPCR, one device may send to another device the operand shown in Figure 4 (operand [1]).

Operate [4]) to set the control value of the bits of the corresponding bit field and transmit the connection management command. For example, if you are only interested in the online bitfield, you can tell the operand to specify only that bit. That is, if the bit position corresponding to the on-line is b0, only the position corresponding to the bit b0 in the operand [operand [1] is set to "1" and all remaining bits are set to "0".

In addition to the arguments according to the connection management formats shown in FIGS. 2 and 3, an operand [n] regarding whether to make a connection private or not can be added to the connection management command structure shown in FIG. .

Therefore, any device (control device) connected by IEEE 1394 transmits to another device (source device or sink device) by designating an output plug or an input plug to the connection management command shown in FIG. / C Defines and sends a new command of the notify command defined in CTS. For reference, there are various forms of AV / C CTS commands. Among them, the notification command sends a notification command from the controller when the controller wants to know the status that will change in the future. ) Is a command that responds to the current state and responds to the controller once more if the target's state changes later.

In the present invention, when the connection management notification command shown in FIG. 4 is transmitted, the device receiving the notification command responds to the device which sends the notification command when any one bit change occurs in the plug control register designated by the connection management command. To send again. The device receiving the response may read information of the corresponding plug control register of the other device, check which bit field has changed, and perform a process corresponding to the changed bit field.

In other words, if the device that received the notification command is a source device with oPCR, if the online bit field first changes from "1" to "0" among the various bit fields of oPCR, the source device no longer outputs the output. Or disconnect the source device as it may be considered not to be exported. On the contrary, when the online bit changes from "0" to "1", the source device can assume that it wants to send the output, so that the source device establishes a connection. For example, when a normal broadcast program ends in the DTV (source device) and no signal is output, the connection of the DTV is terminated.

When the value of the broadcast connection counter or the p2p connection counter in the bit field of the oPCR is changed, it indicates that there is a change in the connection state, such as when another device is overlaid on the already established connection or the attached connection is terminated. If the p2p connection counter value is "1" and the value is changed to "2" because it is a connection set by the source device with the controller, another device receives the information output from the source device. It can be considered to see. In this case, when the connection is set as a private connection, the user may be informed that other people are viewing the information he is viewing so that the user can cope with it appropriately.

When the value of the payload indicating the bandwidth of the information being output in the bit field of the oPCR is changed, appropriate measures may be taken based on the changed output information bandwidth of the source device and the inputtable bandwidth of the sink device. For example, if the bandwidth of the output information transmitted by the source device is large for each bandwidth that the sink device can accept and process, the connection of the sink device can be disconnected so that no more information is received.

Similarly, if the device that received the notification command is a sink device with an iPCR, the control device establishes the connection of the sink device because the sink device can assume that it wants input when the online bit is changed from "0" to "1". On the contrary, the sink device may be disconnected, considering the input is no longer desired. For example, in the video cassette recorder (sink device), when the recordable area portion of the tape is finished and enters the no-signal area portion, the user can be notified immediately so that the user can remove or replace the tape.

As a flowchart according to an embodiment of the connection management method according to the present invention shown in FIG. 5, the connection management method may be performed in a control device having a controller or a device for transmitting a connection management notification command.

According to the procedure defined in IEC 61883, the connection between the source device and the sink device is established (step S101). In this case, the connection may be a point-to-point connection or a broadcast connection.

The connection management notification command is sent to the source device and / or the sink device (step S102). After receiving the current status from the device that received the notification command, waiting for a notification response to the connection management change (step S103), and then changing the bit field of the corresponding plug control register of the device that received the notification command. Receive a notification response to the step (S104).

When the response is received in step S104, first, a change in the online bit field is checked (step S105). If the online bit in the bit field of the plug control register is changed to "0" in step S105, the connection is terminated (step S106).

If the online bit does not change to "0" in step S105, it is checked whether a private connection is set, and whether the value of the broadcast connection counter or p2p counter in the bit field of the plug control register is changed (step S107). If there is a change, it warns the user of the overlay connection so that it can appropriately cope with it (step S108).

If the value of the connection counter does not change in step S107, it is checked whether the payload of the bit field of the plug control register is changed (step S109), and if the payload is changed, the bandwidth is adjusted (step S110). It is checked whether the adjusted bandwidth is acceptable for the sink device inputting information (step S111), and if the adjusted bandwidth is too wide, the connection of the sink device is terminated (step S112), otherwise, a connection management notification command is issued. The transmission proceeds to step S102.

According to the present invention, when one of the devices connected by the digital interface no longer wants to output or accept the input, the connection can be disconnected so that the connection is set up unnecessarily to waste the bandwidth and only when necessary. It can be used to increase the efficiency of bandwidth use.

The present invention can immediately know the various state changes (data transmission / reception status, whether data can be processed) that may occur during the processing of the information of the other device, so that the user can quickly grasp the state changes occurring in the connected devices There is an effect to cope with this.

In addition, the present invention provides information on whether or not the source device wants to transmit information, as well as a change in the number of sink devices connected to the source device, a change in the bandwidth that the source device can output, and a bandwidth that the sink device can input. I can tell you the change. Therefore, when the number of sink devices connected to the source device increases, the user is notified of such a change, and when the other device does not want to connect anymore, the connection of the other device is not allowed to manage the connection state more efficiently. It works.

Claims (23)

delete delete delete delete delete delete delete delete delete (a) establishing a connection between a device connected to a predetermined digital interface and transmitting information through a predetermined data transmission standard and a device receiving the information; (b) sending a connection management notification command to control the connection management state; And (c) controlling the connection when a response to the connection management state change is received. The method of claim 10, wherein the predetermined digital interface is an IEEE 1394 standard, and the predetermined data transmission standard is an IEC 61883 standard. 11. The method of claim 10, wherein in the step (b), the connection management command conforms to a format of a notification command of AV / C audio-video / control command transaction sets (CTS) standard. 11. The method of claim 10, wherein in the step (c), the connection management state change is changed by changing only one of the bit fields of the bit field of the input plug control register and the output plug control register, which is a connection control register defined in the IEC 61883 standard. Connection management method characterized in that the response is received 11. The method of claim 10, wherein in the step (c), if the response indicates that a bit field indicating whether the response is online is changed in the device transmitting the information, the connection management method is terminated or established. The method of claim 10, wherein in the step (c), if the response indicates that the bit field indicating whether the response is online is changed, the connection is terminated or established. 11. The method of claim 10, wherein in step (c), if the response indicates that a payload bit field is changed due to a change in bandwidth of output information in the device transmitting the information, the output is transmitted from the device receiving the information. Connection management method characterized in that the connection is terminated or established according to the acceptance of the bandwidth of the information 11. The method of claim 10, wherein in the step (c), if the response indicates that the connection counter bit field is changed due to a change in the number of devices that receive the information, the device that transmits the information changes. Connection management method, characterized in that the connection is terminated or established. 18. The method of claim 17, wherein step (c) (c1) If the number of devices that receive the information is changed in the device that transmits the information, and if a private connection is established, the device is sent to the user to suppress the transmission of information other than the device that receives the original information. Further comprising the step of informing. A connection management command connected to a predetermined digital interface to notify another device of a state change of the connection when a device establishes a predetermined connection between a device transmitting information and a device receiving information through a predetermined data transmission standard. Is a connection management command structure having a connection register type indicating whether it is an input plug control register or an output plug control register and identification information of the corresponding plug in which a connection is established. 20. The structure of claim 19, wherein the connection management command conforms to a format of an AV / C audio-video / control command transaction sets (AV / C CST) standard. 21. The structure of claim 20, wherein said other device is a device that has sent a connection management notification command. 20. The structure of claim 19, further comprising operands that designate only a portion of the bit fields of the input plug control register or the output plug control register. 20. The connection management command structure according to claim 19, further comprising an operand indicating whether or not to make the connection private.

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