KR20080065068A - Apparatus for receiving digital broadcasting and method of transmitting data - Google Patents

Abstract

An apparatus for receiving digital broadcasting and a method of transmitting data are provided to transmit an encoded transport stream through a common interface by a host controller for reducing cost of the host and speeding communication between the host and a module, thereby improving performance of the digital broadcasting receiver. A host(110) comprises a tuner(111), a demodulator(112), a demultiplexer(113), an MPEG decoder(114) and a host controller(115). The demodulator outputs a scrambled transport stream by demodulating broadcasting signals. An conditional access module includes a descrambler(121), a verifier(123), and a module controller(122). The descrambler outputs the descrambled transport stream, and a common interface is installed at a digital broadcasting receiver for communication between the host and the module. The host transmits the encoded transport stream to the module through the common interface.

Description

Apparatus for receiving digital broadcasting and method of transmitting data}

1 shows a digital broadcast receiver having a conditional access device of the present invention.

2 illustrates an embodiment of communication of a common interface according to the present invention.

3 illustrates another embodiment of a communication method between a host and a module through a common interface according to the present invention.

 * Explanation of symbols for main parts of the drawings

110: host

111: Tuner 112: Demodulator

113: MPEG Decoder 114: Demultiplexer

115: host controller 120: module

121: Descrambler

122: Module Controller

123 Verifier

130: smart card

The present invention relates to the reproduction of digital broadcasting.

Recently, as digital broadcasting is in full swing, standardization works related to transmission and reception of digital broadcasting, such as digital video broadcasting and digital multimedia broadcasting, have been performed.

In addition, a conditional access system has been developed for controlling only authorized viewers to watch the digital broadcast. One of various methods of the conditional access system is based on a standardized common interface between a hardware type module having a descrambling function and a host represented by a digital TV receiver. In this way, the conditional system is configured. Therefore, in such a conditional connection system, it is important to define the common interface.

However, since a preferred method for implementing the common interface has not been proposed yet, there is a difficulty in developing digital broadcasting and its peripherals in earnest.

The present invention has been made to solve the above problems, and an object thereof is to provide a method for efficiently reproducing digital broadcasting.

In order to achieve the above object, the present invention provides a host for receiving a digital broadcast signal, a module for controlling access to the digital broadcast signal, and a common interface for interfacing the host and the module. In the digital broadcast receiver, the host detects an interrupt signal indicating that there is module data to be transmitted by the module and transmits a communication start signal to the module through the common interface to communicate with the module. Initiate, the module generates the interrupt signal, receives the communication start signal, and transmits a response signal including the module data to the module through the common interface when there is the module data to transmit. It provides a digital receiver.

The present invention also provides a common interface comprising a transport stream interface, which is a transport path of a transport stream, and a command interface, which is a transport path of data used to decrypt a transport stream. Include an example.

In addition, the present invention includes an embodiment in which the communication start signal is a "T_Data_Last" object among objects for data transmission, defined in the command interface.

The present invention also includes an embodiment in which the response signal is a "T_SB" object, among the objects for data transmission, defined in the command interface.

Also, when the host has host data to be transmitted to the module, the module may include a "T_Data_More" or "T_Data_Last" object including the host data, among the objects for data transmission, defined in the command interface. It includes an embodiment for transmitting to initiate communication.

The invention also includes an embodiment in which one of the unused pins of the module is used as the pin for the interrupt signal.

The present invention also includes an embodiment in which the pin for the interrupt signal is a CE # 2 pin, and the host transmits the communication start signal to the module when the CE # 2 pin is activated by the module. .

The present invention also provides a data transmission method through a common interface of a digital broadcast receiver including a host for receiving a digital broadcast signal and a module for controlling access to the digital broadcast signal. An interrupt signal generation step of generating an interrupt signal indicating that there is the module data to be transmitted when there is module data to be transmitted to the host; A communication initiation step of the host detecting the interrupt signal transmitting a communication initiation signal to the module through the common interface to initiate communication with the module; And a data transmission step of transmitting a response signal including the module data to the module through the common interface when receiving the communication start signal. to provide.

1 illustrates a digital broadcast receiver having a conditional access device according to the present invention, wherein the digital broadcast receiver includes a host 110 and a conditional access module 120.

Referring to FIG. 1, the host 110 receives a radio frequency signal and outputs a tuner 111 to output a broadcast signal corresponding to a set channel, and the output from the tuner 111. A demodulator 112 for demodulating a broadcast signal to output a scrambled transport stream, and a demultiplexer for demultiplexing a decoded transport stream. 113, an MPEG decoder 114 for decoding and outputting an audio / video stream provided from the demultiplexer 113, and a host controller 115 for controlling the components. do.

The conditional access module 120 also decrypts the decrypted transport stream by decrypting the encrypted transport stream output from the demodulator 112 of the host 110. A verifier 123 for checking the current user's authority by reading user authentication information from an external information medium such as a descrambler 121 and a smart card 130 that is output, and for controlling the components. A module controller 122 and the like.

In addition, the digital broadcast receiver is provided with a common interface that enables communication between the host 110 and the module 120 provided from various broadcasting companies.

In this regard, the common interface is configured based on a specific standard, for example, EN50221 (Common InterfSpecification for Conditional Access and other Digital Video Broadcasting Decoder Applications).

Under the control of the host controller 115, the host 110 transmits the encrypted transport stream to the module 120 along with various commands and decryption data necessary for decryption through the common interface. The module controller 122 of the module 120 controls the descrambler 121 to decrypt the transmitted encrypted transport stream using the transmitted various commands, decrypted data, and the like. The decoded transport stream is transmitted to the host 110 through the common interface together with various data other than the stream data generated in the decoding process.

Specifically, the common interface demodulates a transport stream interface (TSI), which is an interface for the passage between the encrypted / descrambled transport stream and the encrypted transport stream (scrambled). Commands, information, and the like used to descrambled are composed of a command interface, which is an interface to and from the network. The command interface includes a physical layer, a link layer, a transport layer, an application layer, and the like.

In this regard, the communication between the host 110 and the module 120 at the transport layer constituting the command interface always starts from the host 110. As a result, in order for the host 110 to receive data from the module 120 through the command interface, the host 110 should inquire whether the module 120 has data to transmit. Hereinafter, a preferred communication method between the host 110 and the module 120 through a common interface included in the digital broadcast receiver of the present invention will be described with reference to FIGS. 2 and 3.

2 illustrates an embodiment of a communication method between a host and a module through a common interface of the present invention, and illustrates a communication between the host and the module by a polling method.

Currently, the standard related to the common interface of digital broadcasting allows a communication between the host 110 and the module 120 in a command interface using a polling method. Specifically, when the host 110 wishes to send data to the module 120 through the command interface, the host controller 115 may transmit a transport protocol object defined in the transport layer of the command interface. Among them, the control unit is to send the data to the module 120 to put the data on the object used for the transmission of data. The object sent from the host 110 to the module 120 has, for example, an object indicating that there is more data to send (eg, a "T_Data_More" object), an object indicating that it is the last data to send (eg , A "T_Data_Last" object).

The size of data that can be sent at one time through the transport layer is limited. Therefore, when the host controller 115 wants to transmit data larger than a limited size in the transport layer, the host controller 115 divides the data and sends the divided data to the module 120. For example, when data is divided into three times and sent to the module 120, the host controller 115 may transmit objects including the divided data in the order of "T_Data_More-> T_Data_More-> T_Data_Last". Sent to). As such, when there is data that the host 110 wants to send to the module 120, the restriction that only the host 110 can start communication is not a big problem.

On the contrary, if the module 120 has data to be sent to the host 110, the host 110 should start communication first, and thus the host 110 according to the embodiment of FIG. For example, the module 120 is polled at a maximum of 100 ms. In detail, the host controller 115 periodically sends a "T_Data_Last" object to the module 120 when there is no data to be sent, and the module controller 122 of the module 120 responds with a response object (eg, "T_SB" object) is sent to the host 110 via the command interface.

That is, in the polling method, when there is no data to be specifically transmitted by the host 110, the "T_Data_Last" object is transmitted from the host 110 to the module 120 and the "T_SB" from the module 120 to the host 110. "The object transfer is repeated. When there is no data to be sent to the host 110, the module controller 122 may receive a dummy "T_SB" object ("T_SB (no data)) having no data in response to the" T_Data_Last "object. Is transmitted to the host 110, and if there is data to be sent, a "T_SB" object ("T_SB (data)) including the data is sent to the host 110.

The common interface defined in the current standard makes it possible to exchange data between the host 110 and the module 120 through a command interface using the above-described polling scheme. However, according to the polling method, since the host 110 needs to poll the module 120 periodically, the burden on the host 110 is increased. In addition, the polling structure requires a certain latency time (average period / 2) due to object exchange between the host 110 and the module 120.

Accordingly, in order to solve the above problem, the present invention provides a common interface using an interrupt method, rather than a communication through a polling method.

FIG. 3 illustrates another embodiment of a method of communication between a host and a module through a common interface of the present invention, and in accordance with the present invention, the host 110 and the module 120 in a common interface employing an interrupt method. It shows communication between.

Referring to FIG. 3, when the module 120 has data to be sent to the host 110, use of a plurality of pins corresponding to a kind of physical interface of the conditional access module adopting the common interface may occur. An interrupt signal is sent to the host 110 using an undefined pin.

For example, if a common interface is configured in accordance with EN50221, the physical layer of the command interface will have a plurality of pins, of which pins for which the use is not yet defined, for example, the CE # 2 pin. Can be used as an instrument pin.

When using the CE # 2 pin as an interrupting pin, when there is data to be sent from the module 120 to the host 110, the module controller 122 activates the CE # 2 pin. (Also called an assert). When the host controller 115 of the host 110 detects the interrupt signal, that is, detects that the CE # 2 pin is activated, the transmission defined in the transport layer, as described in FIG. A protocol object, for example, a "T_Data_Last" object is sent to the module 120. The module controller 122 of the module 120 that receives the "T_Data_Last" object sends data to the host 110 through the "T_SB" object.

As a result, in the embodiment of FIG. 2, the host 110 periodically polls the module 120 in preparation for a situation in which the module 120 wants to send data. In contrast, in the embodiment of FIG. 3, the host 120 transmits a "T_Data_Last" object to the module 120 only when detecting an interrupt signal to start communication for data transmission.

In the case of adopting the common interface having the interrupt method described in FIG. 3, when the host 110 receives the interrupt signal from the module 120, the host 110 sends “T_Data_Last” to the module 120 to receive data. In this case, the burden on the host 110 may be reduced compared to the case in which the "T_Data_Last" signal is periodically transmitted to the module 120. In addition, in the polling method, the module 120 receives the "T_Data_Last" object from the host 110 and searches whether there is data to be sent after the communication is started, and accordingly, the host 120 responds with the "T_SB" object. ), A latency time occurs. Therefore, in the interrupt method, since the interrupt signal is generated when the module 120 has data to be transmitted, the communication speed is improved compared to the polling method.

Therefore, when the common interface is interrupted according to the present invention, the performance of the digital broadcast receiver employing the common interface is generally improved.

The present invention is not limited to the above-described embodiments, and as can be seen in the appended claims, modifications can be made by those skilled in the art to which the invention pertains, and such modifications are within the scope of the present invention.

According to the common interface and the data transmission method through the digital broadcast receiver according to the present invention described above, the burden on the host is reduced, and the communication speed between the host and the module is increased. Therefore, the overall performance of the digital broadcast receiver employing the common interface is improved.

Claims (13)

A digital broadcast receiver comprising a host for receiving a digital broadcast signal, a module for controlling access to the digital broadcast signal, and a common interface for interfacing the host and the module. , The host detects an interrupt signal indicating that there is module data to be transmitted by the module and transmits a communication start signal to the module through the common interface to initiate communication with the module; The module generates the interrupt signal when there is the module data to be transmitted, receives the communication start signal, and transmits a response signal including the module data to the module through the common interface. receiving set. The method of claim 1, The common interface is a digital broadcast comprising a transport stream interface, which is a transport path of a transport stream, and a command interface, which is a transport path of data used for decoding a transport stream. receiving set. The method of claim 2, And the communication start signal is a "T_Data_Last" object, among objects for data transmission, defined in the command interface. The method of claim 2, The response signal is a digital broadcast receiver, characterized in that the "T_SB" object, among the objects for data transmission, defined in the command interface. The method of claim 2, When there is host data to be transmitted to the module by the host, among the objects for data transmission defined in the command interface, a "T_Data_More" or "T_Data_Last" object including the host data is transmitted to the module for communication. And a digital broadcasting receiver. The method of claim 1, And one of the unused pins of the module is used as a pin for the interrupt signal. The method of claim 6, And the pin for the interrupt signal is a CE # 2 pin, and the host transmits the communication start signal to the module when the CE # 2 pin is activated by the module. In the data transmission method through a common interface of a digital broadcast receiver comprising a host for receiving a digital broadcast signal (host) and a module for controlling access to the digital broadcast signal, An interrupt signal generation step of generating an interrupt signal indicating that the module data to be transmitted is present when there is module data to be transmitted to the host; A communication initiation step of the host detecting the interrupt signal transmitting a communication start signal to the module through the common interface to initiate communication with the module; And And a data transmission step of transmitting a response signal including the module data to the module through the common interface upon receiving the communication start signal. The method of claim 8, The communication start signal is a "T_Data_Last" object among objects for data transmission, which is defined in a command interface constituting the common interface, through a common interface of a digital broadcast receiver. Data transmission method. The method of claim 8, The response signal is "T_SB" among the objects for data transmission defined in the command interface constituting the common interface, the data transmission method through a common interface of the digital broadcast receiver. The method of claim 8, If there is host data to be transmitted to the module by the host, the module may include a "T_Data_More" or "T_Data_Last" object including the host data, among the objects for data transmission, defined in the command interface constituting the common interface. Transmitting the data through a common interface of a digital broadcasting receiver. The method of claim 8, And using one of the unused pins of the module as a pin representing the interrupt signal. The method of claim 12, The pin representing the interrupt signal is a CE # 2 pin, and the host transmits the communication start signal to the module when the CE # 2 pin is activated by the module. Data transmission method through.

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