KR100313769B1 - Isochronous data control method - Google Patents

Abstract

The present invention relates to an isochronous data control method for retrieving a register value of a mode node connected to an IEEE1394 bus to eliminate unnecessary transmission channels. Such an isochronous data control method includes the steps of: checking a predetermined register managing a transmission bandwidth and a channel number of nodes by a system administrator, retrieving an output plug control register of the nodes, and then table the predetermined information; Retrieving an input plug control register of a predetermined node including a corresponding channel for the retrieved node after creating a table, and adding predetermined information to the retrieved table of the output plug control register; And searching the table to change unused transmission bandwidth and channel number when the transmission channel continuously occupies the transmission bandwidth in a state where a destination is not determined between nodes and transmitting isochronous data through the changed transmission channel. Thus, there is an advantage to expect a smooth transmission of isochronous data.

Description

Isochronous data control method

The present invention relates to data transmission control, and more particularly, to a control method of isochronous data generated between devices in accordance with the Institute of Electrical & Electronic Engine (IEEE 1394) transmission mode.

In general, the IEEE 1394 multimedia transmission standard is established as a transmission technology or standard between digital devices, and is capable of transmitting and receiving multimedia data at high speeds from 100 Mbps to 1 Gbps by connecting communication devices, computers, and home appliances in a single network. Is the interface specification.

This IEEE1394 is superior to Universal Serial Bus (USB), which is emerging as a multimedia standard, and has superior transmission speed and bidirectional communication. That is, IEEE1394 can process data at three transmission speeds such as 100Mbps, 200Mbps, and 400Mbps according to the transmission mode, and accordingly, it can smoothly transmit digital audio or moving image information, so multimedia such as scanner, digital camera, digital video camera, etc. Peripheral devices can be connected and used. In addition, since the three transmission rates are compatible with other transmission rates, for example, the 400 Mbps transmission mode supports both transmission modes of 10 Mbps and 20 Mbps.

In addition, because of its excellent bi-directional communication function, a peripheral device with an integrated circuit (IC) capable of controlling an IEEE1394 interface, that is, a node, can transmit and receive data smoothly in a multimedia application field such as a video conference through a computer.

On the other hand, IEEE 1394 can be plug and play (PnP) and hot-plug (Hot-Plug), it is possible to access or delete a new peripheral device while the peripheral device connected to the IEEE 1394 cable is in operation.

The data transmission process of a plurality of nodes interconnected according to the IEEE1394 transmission mode in which such a high transmission speed and various functions are provided will be described with reference to FIG. 1.

1 is a diagram illustrating an embodiment in which a plurality of devices are interconnected according to a general IEEE1394 transmission standard. As shown in FIG. 1, each node transmits and outputs data output from one node to another node for recording or display. Input / output modules (not shown) are provided and interconnected by a two-point connection method (Point-to-Point). That is, a video cassette record (VCR) 10, a digital TV (DTV) 12, a set-top box 14, a computer 16, a printer 18, a scanner 20 and The video cameras 22 are interconnected using a point-to-point bus technology.

In the network configured as described above, data transmission of predetermined information is performed according to the asynchronous transfer or isochronous transfer mode supported by IEEE1394.

For example, in accordance with a transmission channel assigned an isochronous transmission mode, the video camera 22 captures a moving picture or a still picture of a subject through a predetermined lens, converts the captured image expression into a digital signal, and then the video camera. The data is transmitted to the computer 16 in accordance with the driving clock frequency applied to the data.

The computer 16 transmits the digital signal to the digital TV 12 via the set-top box 14 or displays it or records using the VCR 10.

It is also possible to output predetermined image information captured by the printer 18.

At this time, the signal processing between each node is a digital signal, and does not need to be converted to digital separately.

Meanwhile, as described above, in the state where each node transmits data to each other by the IEEE1394 interface, when a new node is added and connected, or when any one node among previously connected nodes is removed, the network configuration is performed together with the bus initialization. This is readjusted. That is, when a node is connected to or disconnected from the bus for active operation of a given bus for transmission of isochronous data on an IEEE1394 bus, and whenever any node connected to the bus is off Since the initialization is performed again, each node is given a physical address again instead of all existing information that has been transmitted data in the entire network.

In this case, when it is necessary to designate a root node, priority can be assigned to a specific node in consideration of whether a cycle master is available or a bus master is available. After the root node is configured, each node informs itself of its existence through the network. Through this process, all node information is collected and then the IEEE1394 interface enters the standby state to start normal operation.

In the case of isochronous data, the isochronous stream before the bus has completed the self-identification process, and the isochronous packet must be transmitted again in the bandwidth and channel number before the reset after 125ms. .

That is, in a predetermined node capable of transmitting isochronous data, even if the power of the node is turned off, the IEEE1394 module provided to each node initializes the channel number and transmission bandwidth provided for isochronous transmission, and also inputs / outputs a predetermined node. Each I / O Master Plug Register and I / O Plug ControlRegiter provided in the module is updated to turn off the corresponding link, but vice versa. In order to transfer the data between them, the physical layer should continue to operate in the OSI (Open System Interconnection) 7-Layer.

However, if a transmission cable is disconnected from a predetermined node or a corresponding time is continued for a long time while transmitting data among a plurality of nodes connected on an IEEE1394 bus, the transmission channel does not have a destination of isochronous data transmission. This continues to occupy the transmission bandwidth, and there is a case where the values of the mast flag register and the flag control register provided to the node to control the flow of the isochronous data do not coincide, thereby controlling the isochronous data transmitted via the IEEE1394 bus. There was no problem.

Accordingly, the present invention provides a case in which an unnecessary transmission channel occupies a transmission bandwidth or is provided to a node during the isochronous data transmission between nodes in the IEEE1394 transmission mode, and a field value of a register controlling the transmission and reception of isochronous data is inconsistent. It is an object of the present invention to provide a method for controlling isochronous data such as changing a transmission bandwidth, a channel number and a register value of a node, and modifying a plug required for data transmission between nodes.

1 is a diagram illustrating an embodiment in which a plurality of devices are interconnected according to a general IEEE1394 transmission standard.

2 is a state diagram illustrating an embodiment in which isochronous data is transmitted between a plurality of devices connected to an IEEE1394 bus according to the present invention.

FIG. 3 is a format configuration diagram of an input / output plug control register for controlling the flow of isochronous data of FIG. 2.

3A is a format diagram of an input plug control register;

3B is a format diagram of an output plug control register;

FIG. 4 is a format configuration diagram of an input / output master plug register for controlling the flow of isochronous data of FIG. 2.

4A is a format diagram of an input master plug register;

4B is a format diagram of an output master plug register;

5 is a flowchart illustrating a process of transmitting isochronous data according to the present invention.

* Explanation of symbols for main parts of the drawings

100 to 100n: first to nth AV nodes

An isochronous data control method according to the present invention for achieving the above object is a transmission method for transmitting mutual isochronous data by connecting a plurality of nodes to the IEEE1394 cable; Examining predetermined registers that manage transmission bandwidths and channel numbers of the nodes, retrieving the output plug control registers of the nodes, and then table the predetermined information; Retrieving an input plug control register of a predetermined node including a corresponding channel for the retrieved node after creating the table, and adding predetermined information to the retrieved table of the output plug control register; And searching the table to change an unused transmission bandwidth and channel number when the transmission channel continuously occupies a transmission bandwidth in a state where a destination is not determined between the nodes, and changing the isochronous data through the changed transmission channel. Transmitting.

Preferably, the predetermined information is a channel number owned by the node, a two-point side counter and a broadcast connection counter.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a state diagram showing another embodiment in which data is transmitted between a plurality of devices connected to an IEEE1394 bus according to the present invention. As shown in FIG. 2, a plurality of AV nodes 100-100n are connected to the IEEE1394 bus. The AV nodes 100-100n include input / output master plug registers (I / O MPRs).

In addition, the input / output master plug register (I / O MPR) includes input / output plug control registers (I / O PCR), respectively, so that isochronous data is provided to the respective AV nodes 100 to 10On. 0 Transmit / receive via IEEE1394 bus according to the operation of MPR and I / O PCR.

In addition, a series of operations using a plug control register or the like for controlling the transmission of isochronous data is set according to a connection management procedure (CMP).

As described in the related art, the isochronous data is an AV device that receives predetermined data generated from the AV node itself or other AV devices, for example, the AV node, to any one AV node. It is processed according to the transmission channel of the bus. The transport channel cannot transmit more than one data, so each isochronous data is transmitted / received on one transport channel.

In addition, in order to transmit isochronous data between two AV nodes on an IEEE1394 bus, a predetermined operation for connecting an input / output plug of an AV device using an isochronous channel is required. Accordingly, an audio signal / video signal is converted into a digital signal. In order to transmit to the network, the processing speed and synchronization of the device are required, and a transmission path capable of isochronous transmission is required.

3 is a format configuration diagram of an input / output plug control register for controlling the flow of isochronous data of FIG. 2, and FIG. 4 is a format configuration diagram of an input / output master plug register for controlling the flow of isochronous data of FIG. 2. Is showing each.

Here, the format diagram shown in each diagram represents 'definition', 'initial value', 'bus reset and connand reset value', 'read value' and 'lock effect', respectively.

As described above, a control process of isochronous data transmitted between nodes on an IEEE1384 bus using a plug control register and a master plug register is described as follows.

First, when isochronous data is transmitted from a predetermined AV node 100 to another AV node 100, it is transmitted to an input plug of the AV node 100 through an output plug provided to the AV node 100.

The isochronous data transmission through the output plug of the AV node 100 is controlled by the output plug control register and the output master plug register of the AV node 100, and for controlling the input / output plugs provided to the AV node. One output master plug register is provided.

The output master plug register controls a characteristic common to all isochronous data to be transmitted to a predetermined AV node, and the output plug control register controls a characteristic of any one isochronous data. The isochronous data is separate from other isochronous data transmitted from the AV node.

On the other hand, isochronous data transmitted from the output plug is transmitted to the input plug of the AV node 100n via an IEEE1394 bus, where isochronous data reception through the input plug is performed as described above in the input plug. It is controlled by an input plug control register and an input master plug register provided at.

The input master plug register controls common characteristics for all isochronous data transmitted from the AV node 100, and the input plug control register controls the characteristics of any one isochronous data.

In this way, a plurality of AV nodes 100 to 100n are connected to the IEEE1394 bus, and while the isochronous data is transmitted / received through the input / output plugs provided to the respective nodes (ST100), the power supply of any one AV node. When this is turned off or when a transmission cable is disconnected from a predetermined node and data transmission is not possible, a system manager or bus manager (not shown) may transmit the transmission bandwidth register and channel number register of each AV node and the AV node. The channel number, the two-point connection, and the simultaneous transmission connection counter are respectively searched to find out whether the plugs of the corresponding AV nodes which transmit / receive isochronous data are set correctly (ST102) (ST104) (ST106).

In other words, if the values of the register and the channel number do not match, it is necessary to change these values to transmit isochronous data.

The searching process first searches the output plug control registers of all AV nodes connected to the IEEE1394 bus. The channel number (6 bits), the two-point connection counter (6 bits) and the simultaneous transmission connection of the output plug control registers are searched. Retrieves the area value of the counter (1 bit).

Subsequently, the output plug control registers of all the AV nodes are output and transmitted to a plurality of nodes through the IEEE 1394 bus. In this case, predetermined information of the input plug control register of the corresponding transmission channel, for example, search information of the output plug control registers, is transmitted. Retrieve the same information as

The bit values constituting the channel number of the input plug control register, the two-point connection counter and the simultaneous transmission connection counter are the same as the bit values of the output plug control register.

Each information retrieved from the input plug control register is added to and included in a predetermined table created by searching the output plug register.

Subsequently, after searching the input / output plug control registers provided to the AV nodes 100 to 100n, each item for each input / output master plug register controlling the input / output plug control register is searched. .

The input / output plug control register generally includes items indicating a data rate (2 bits) of isochronous data transmitted from an AV node, a number of channels (6 bits) capable of simultaneous transmission, a number of input / output plugs (5 bits), and the like. This is provided.

Here, the number of channels that can be transmitted simultaneously is determined by the isochronous channel number when a connection capable of simultaneously outputting isochronous data without a connection between the two points of the plug and the plug is set in the output plug included in the corresponding mast plug register. Is determined.

That is, 'B' is a simultaneous transmission channel base area value, and 'N <i:' is defined as an isochronous channel number. B + 1) mod63 ',' B = 63: N [i] = 63 '.

Subsequently, the value of the corresponding AV node transmitted / received by the input / output plug is compared according to a predetermined table in which the register values of all AV nodes connected to the IEEE1394 bus are summarized. Search for the relevant input / output plug for the case of the error (STl08).

Subsequently, the searched bandwidth and channel number for which data transmission is not performed in the input / output plugs provided to the searched plug, for example, an AV node transmitting / receiving isochronous data, are deleted or changed into corresponding information (ST110). (ST112).

In addition, the isochronous data transmission may be continuously performed through the changed transmission plug.

In this embodiment, in case of disconnection of the IEEE 1394 bus or other error condition, the register value provided to the transport plug of the mode node connected to the IEEE 1394 bus is searched, and the transmission channel which is not necessary after the search is searched. To change.

In addition, although specific embodiments of the present invention have been shown above, it is obvious that the present invention may be variously modified and implemented by those skilled in the art.

Such modified embodiments should not be individually understood from the technical spirit or the prospect of the present invention, and such modified embodiments should fall within the appended claims of the present invention.

As can be seen from the above description, during the isochronous data transmission between nodes in the IEEE 1394 transmission mode, unnecessary transport channels occupy the transmission bandwidth or the field values of registers provided to the nodes to control the transmission and reception of isochronous data are inconsistent. In this case, it is possible to expect smooth transmission of isochronous data by changing the transmission bandwidth, channel number and register values of each node and modifying plugs necessary for data transmission between nodes.

Claims (2)

A method for controlling isochronous data transmitted between nodes by connecting a plurality of nodes to an IEEE1394 cable; Inspecting, by a system administrator, a predetermined register managing the transmission bandwidth and channel number of the nodes, retrieving the output plug control registers of the nodes, and tabulating the predetermined information; Retrieving an input plug control register of a predetermined node including a corresponding channel for the retrieved node after creating the table, and adding predetermined information to the retrieved table of the output plug control register; And searching the table to change an unused transmission bandwidth and channel number when the transmission channel continuously occupies a transmission bandwidth in a state where a destination is not determined between the nodes, and changing the isochronous data through the changed transmission channel. Isochronous data control method comprising the step of transmitting. The isochronous data control method according to claim 1, wherein the predetermined information is a channel number owned by the node, a two-point connection counter and a broadcast connection counter.