KR20010088879A - Digital television system - Google Patents

Abstract

PURPOSE: A digital television system is provided to comprise an IEEE(Institute of Electrical and Electronic Engineers) 1394 interface supporting a communication function of a full duplex mode. CONSTITUTION: An antenna(100) receives an RF signal transmitted through a digital satellite or an airborne wave. A tuner(120) selects a desired channel from signals received from the antenna. A demultiplexor(130) separates video and audio signals from signals output from the tuner(120). An audio decoder(210) decodes audio signals separated by the demultiplexor. A video decoder(220) decodes video signals separated by the demultiplexor. An IEEE 1394 interface(300) interfaces the demultiplexor and an IEEE 1394 cable, and a first port for transmitting signals received through the cable to the audio decoder or the video decoder, and a second port for transmitting a signal selected by the tuner to the IEEE cable.

Description

Digital Television System {DIGITAL TELEVISION SYSTEM}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to digital television systems and, more particularly, to digital television systems comprising an Institute of Electrical and Electronic Engineers (IEEE) 1394 interface device.

As the digital video revolution becomes visible, there is a demand for high-speed digital interfaces between consumer electronics products. Examples of such requests include set-top boxes, televisions, and digital video cassette recorders using a moving picture expert group (MPEG) -2 transfer stream (hereinafter referred to as TS). Control and data interfaces between DVCR, digital video camcorders (DVCs), computers and peripherals.

The IEEE 1394 interface is based on the IEEE 1394 protocol and is one of the most popular interfaces for such a high speed digital interface.

1 is a diagram showing a conventional application using the IEEE 1394 interface.

In FIG. 1, a conventional application using the IEEE 1394 interface includes a source generator 10, a display 20 (or a storage), and an IEEE 1394 interface 30. As shown in FIG.

The source generator 10 generates a video signal in the form of a transfer stream (hereinafter referred to as a TS), and transmits the generated signal to the display unit 20 (or the storage unit) or the IEEE 1394 interface unit ( 30) to the physical layer (IEEE 1394 cable).

The display unit 20 displays a video signal transmitted from the source generator 10 or transmitted from the outside through the IEEE 1394 interface unit 30.

The IEEE 1394 interface unit 30 is for interfacing the signal from the source generator 10 to the outside (physical layer) or the signal from the outside to the display unit 20.

FIG. 2 is a diagram showing details of the IEEE 1394 interface unit 30 shown in FIG.

As shown in FIG. 2, the conventional IEEE 1394 interface unit 30 includes an interface 31, a receiver 32, a cycle redundancy check (CRC) checker 33, a transmitter 34, a reception controller 35, It consists of a cycle monitor 36, a cycle timer 37, a transmission controller 38, and buffers 39, 40.

In Fig. 2, the signal received from the physical layer is received by the receiver 32 via the interface 31, and the CRC checker 33 checks whether the received signal is in error. An isochronous signal (hereinafter, referred to as an "ISO" signal), such as a moving image data signal, is received from the received error-checked signal through the receiving controller 35 to the buffer 39, and an asynchronous signal is received. It is sent to the buffer 40 through the controller 35. In addition, the reception controller 35 transmits a signal received from the receiver 32 to the cycle monitor 36, which monitors the timing of the received signal.

The buffer 39 is a first-in first-out (FIFO) memory for temporarily storing received and transmitted signals of an ISO signal. The buffer 39 is used as an isochronous receiving FIFO (IRF) memory at the time of reception, and isochronous transmitting at the time of transmission. FIFO) memory. The received ISO signal passing through the buffer 39 is transmitted to the display unit 20 shown in FIG.

The buffer 40 is a FIFO memory for temporarily storing reception and transmission signals of an asynchronous signal, and is used as an Asynchronous Receiving FIFO (ARF) memory at the time of reception, and is used as an Asynchronous Transmitting FIFO (ATF) memory at the time of transmission. The received asynchronous signal passing through the buffer 40 is transmitted to a microcontroller (microcomputer) for controlling the overall operation.

Meanwhile, an ISO transmission signal such as a moving picture generated by the source generator 10 of FIG. 1 is temporarily stored in the buffer 39. At this time, a port for transmitting and receiving signals between the buffer 39 and the source generator (or the display) uses one bidirectional port. Therefore, although ISO signals can be transmitted and received in both directions, communication in both directions cannot be performed at the same time.

The ISO signal passing through the buffer 39 is transmitted to the transmitter 34 through the transmission controller 38. At this time, the transmission controller 38 sets the synchronization timing of the ISO transmission signal according to the time information of the cycle timer 37, and transmits it to the transmitter 34. FIG. The timing-adjusted ISO signal output from the transmitter 34 is transmitted by the CRC checker 33 to the physical layer by adding a CRC code for error checking.

Meanwhile, the conventional IEEE 1394 interface unit 30 shown in FIGS. 1 and 2 basically supports only a half duplex communication method and does not support a full duplex communication method.

That is, as shown in FIG. 3A, the video signal generated from the source generator 10 is transmitted to the display unit 20 and simultaneously to other household appliances through the IEEE 1394 interface unit 30 and the physical layer. As shown in 3b, the video signal generated from the external home appliance is received by the display unit 20 through the IEEE interface unit 30. However, since the conventional IEEE 1394 interface has only one bidirectional port, the signal generated from the source generator 10 is transmitted to the physical layer through the IEEE 1394 interface unit 30, and at the same time, the signal received from the physical layer is interfaced. Transmission through the unit 30 to the display unit 20, that is, full duplex communication was not possible.

Therefore, the conventional IEEE 1394 interface has a problem that the interactive application such as picture-in-picture (PIP) or TV phone (phone) is not implemented.

An object of the present invention is to overcome the above problems, and to provide a digital television system including an IEEE 1394 interface that supports a full duplex communication function.

1 is a diagram showing a conventional application using the IEEE 1394 interface.

FIG. 2 is a diagram showing details of the IEEE 1394 interface of FIG.

3A and 3B illustrate an example of implementation of a conventional IEEE 1394 interface unit.

4 is a block diagram of a digital TV system according to an embodiment of the present invention.

5 is a detailed block diagram of an IEEE 1394 interface unit according to an embodiment of the present invention.

FIG. 6 is a detailed view of the port switch of FIG.

7A and 7G are diagrams illustrating an implementation example of a port switch according to an embodiment of the present invention.

In order to achieve the above object, the present invention provides a dual system including an IEEE 1394 cable and a first system having a source generator for generating an isochronous video signal and a display for displaying the video signal generated by the source generator. Interface by communication.

To this end, a digital television system according to one aspect of the invention,

An antenna for receiving a radio frequency signal transmitted through a digital satellite or airwave; A tuner unit for selecting a desired channel among the signals received from the antenna; A demultiplexer for separating an audio signal and a video signal from a signal output from the tuner unit; An audio decoder for decoding the audio signal separated by the demultiplexer and outputting the decoded audio signal to a speaker; A video decoder for decoding a video signal separated by the demultiplexer and outputting the decoded video signal to a display; And a first port for interfacing the demultiplexer with an IEEE 1394 cable and transmitting a signal received from the outside through the IEEE 1394 cable to the audio decoder or the video decoder and a signal selected by the tuner unit to the IEEE cable. It includes an IEEE 1394 interface device having a second port for.

Hereinafter, with reference to the drawings will be described an embodiment of the present invention;

4 is a block diagram of a digital TV system according to an embodiment of the present invention.

As shown in FIG. 4, a block diagram of a digital TV system according to an exemplary embodiment of the present invention includes an antenna 110, a tuner unit 120, a demultiplexer 130, an audio decoder 210, a video decoder 220, It consists of a central processing unit (CPU) 400 and an IEEE interface unit 300. In FIG. 4, the antenna 110, the tuner 120, and the demultiplexer 130 form the source generator 100, and the audio decoder 210 and the video decoder 220 form the display 200.

The antenna 110 receives a radio frequency (RF) signal transmitted through a digital satellite or airwaves, and the tuner unit 120 selects a desired channel from the RF signals received from the antenna, and converts the selected signal into an intermediate frequency band. frequency (IF). Also, the tuner unit 120 performs forward error correction (FEC) on the IF signal.

The demultiplexer 130 selects a corresponding program from the signals output from the tuner unit 120, separates the audio signal and the video signal, and outputs the audio signal to the audio decoder 210 and the video decoder 220, respectively. In addition, the demultiplexer 130 transmits a signal output from the tuner unit 120 to the physical layer (IEEE 1394 cable) through the IEEE 1394 interface unit 300, and a signal transmitted from the outside through the IEEE 1394 interface unit 300 The audio signal is separated into an audio signal and a video signal, and then transmitted to the audio decoder 210 and the video decoder 220, respectively.

The audio decoder 210 and the video decoder 220 decode the audio signal and the video signal output through the demultiplexer 130 and output the decoded audio signal to the speaker and the display, respectively. The CPU 400 controls operations of the tuner 120, the demultiplexer 130, the audio decoder 210, and the display 220 through the bus BUS.

Meanwhile, the IEEE 1394 interface 300 of the digital TV system according to an embodiment of the present invention transmits a signal from the physical layer to the demultiplexer 130 and at the same time, a full duplex communication method for transmitting a signal from the demultiplexer to the physical layer. This is possible. FIG. 5 is a diagram illustrating in detail an IEEE 1394 interface 300 capable of full duplex communication.

As shown in FIG. 5, the IEEE 1394 interface 300 according to the embodiment of the present invention includes an IEEE 1394 interface 310, a receiver 320, a CRC checker 321, a transmitter 330, and a reception controller 340. ), Cycle monitor 341, cycle timer 342, transmission controller 350, IRF buffer 361, ITF buffer 362, ARF buffer 363, ATF buffer 364, RCPB 371, TSIB 372, a port switch 380, and an interface 390.

In FIG. 5, a signal received from the physical layer is received by the receiver 320 through the IEEE 1394 interface 310, and the CRC checker 321 checks whether the received signal is in error and discards the packet data in error. .

An isochronous (ISO) signal, such as a moving image data signal, of the received error-checked signal is transmitted to the isochronous receive buffer (IRF) 361 through the reception controller 340, and the asynchronous signal is received in the reception controller 340. Is sent to the asynchronous receive buffer (ARF) 363 via.

In addition, the reception controller 340 transmits the received signal to the cycle monitor 341, which monitors the timing of the received signal.

The reconstruction packet block (hereinafter, referred to as 'RCPB') 371 analyzes time stamp information of a received ISO signal that has passed through the IRF buffer 361 to relocate (recover) the location of packet data. Thereafter, the recovered signal is transmitted to the port switch 380. The recovered received ISO signal transmitted to the port switch 380 is transmitted to the demultiplexer 130 of FIG. 4 through the bidirectional port A or the unidirectional port B. FIG. As described above, the signal transmitted to the demultiplexer 130 is divided into an audio signal and a video signal, and then transmitted to the speaker and the display through the audio decoder 210 and the video decoder 220, respectively.

The received asynchronous signal via the ARF buffer 363 is transmitted to the CPU 400 of FIG. 4 via the interface 363.

Meanwhile, the ISO signal transmitted from the demultiplexer 130 of FIG. 4 is received by the time stamp insertion block (hereinafter referred to as TSIB) 372 through the bidirectional port A, and the TSIB 372. Adds a time stamp indicating the position of the packet data of the transmission ISO signal as header information, and transmits it to the ITF buffer 362, and the ITF buffer 362 temporarily stores the transmission ISO signal.

The ISO signal passing through the ITF buffer 362 is transmitted to the transmitter 330 through the transmission controller 350. At this time, the transmission controller 330 adjusts the synchronization timing of the ISO transmission signal according to the time information of the cycle timer 342, and transmits it to the transmitter 330. The ISO signal whose synchronization timing is adjusted from the transmitter 330 is added to the physical layer through the IEEE 1394 interface 310 by adding a CRC code for error checking by the CRC checker 321.

As described above, the IEEE 1394 interface unit 300 shown in FIG. 5 is a bidirectional port A capable of transmitting bidirectional signals between the demultiplexer (source generator) 130 and the physical layer, and the demultiplexer (display unit) from the physical layer. It has a port switch 380 having a unidirectional port B which can only transmit to the network, thereby enabling full duplex communication.

That is, when the video signal is transmitted from the source generator 100 to the physical layer and at the same time to use full duplex communication for transmitting a signal received from the physical layer to the display unit 200, the source generator 100 to the physical layer. The signal transmission can be performed by using the bidirectional port switch A and the signal transmission from the physical layer to the display 300 by using the unidirectional port switch B.

6 is a diagram showing an example of a port switch capable of such a full-duplex communication method.

As shown in Fig. 6, a port switch according to an embodiment of the present invention includes an AND gate 381 and 382, a multiplexer 385, a transfer gate 386 and 384, and a buffer 383.

In Fig. 6, the ISO signal transmitted from the RCPB 371 is transmitted to one input terminal of the AND gate 382 and one input terminal of the multiplexer 385, and enable signal En (A) of port A. Is supplied to the other input terminal of the AND gate 382 and one input terminal of the AND gate 381.

The output signal of the AND gate 382 is connected to the transfer gate 384, and the output signal of the transfer gate 384 is output to the demultiplexer (or the display) through the bidirectional port A. At this time, the transmission gate 384 determines whether or not the signal is transmitted by the enable signal En0.

On the other hand, the ISO signal from the demultiplexer (or source generator) is transmitted to the buffer 383 through the bidirectional port A, and the output signal of the buffer 383 is coupled to the other input terminal of the AND gate 381 and the multiplexer 385. Is supplied to the other input terminal. The output signal of the AND gate 381 is output to the TSIB 372.

The multiplexer 385 outputs one of two signals input to the input terminal by the select signal Sel, and the output signal of the multiplexer 386 passes through the unidirectional port B through the transmission gate 386 to the demultiplexer (or Display). At this time, the transmission gate 386 determines whether to transmit a signal by the enable signal En (B) of the port B.

According to the port switch shown in FIG. 6, various types of signals can be transmitted by the enable signals En (A), En (B), and En0, and the multiplexer selection signals, which are illustrated in FIGS. 7A to 7G. It demonstrates with reference.

7A and 7G are diagrams illustrating an implementation example of a port switch according to an embodiment of the present invention.

First, in the embodiment illustrated in FIG. 7A, when the ISO signal from the source generator 100 (multiplexer) is transmitted to the TSIB through the port switch 380, the signal is not transmitted from the RCPB to the display 200. Indicates. The implementation of the transmission of the signal shown in Fig. 7A enables the AND gates 381 and 382 with the enable signal En (A) high, and the enable signals En (B) and En0 low, respectively. The transmission of the transfer gates 386 and 384 may be interrupted.

On the other hand, for the transmission of the signal shown in Fig. 7B, the enable signals En (A) are set to the high state to enable the AND gates 381 and 382, and the enable signals En (B) are made high. State to enable transmission of the transmission gate 384. Then, the ISO signal transmitted from the TSIB signal is transmitted to the display unit through the bidirectional port A. Then, the enable signal En0 is transmitted low. The transmission of the gate 386 may be interrupted.

Similarly, in order to implement the transmission of the signal shown in Fig. 7C, the enable signal En (A) is set to the high state to enable the AND gate 381. Further, the selection signal of the multiplexer 385 is used. The output signal of the transfer gate 383 is selected and the enable signal En0 is set to the high state to enable the transfer gate 386. In this case, the signal generated by the source generator 100 causes port A At the same time as the transmission through the TSIB, it is transmitted to the display unit 200 through the port B.

7F and 7G show examples of signal transmissions representing a full duplex communication scheme. To implement the transmission of the signals shown in Figs. 7F and 7G, the enable signal En (A) is made high to enable the AND gate 381. Further, the selection signal of the multiplexer 385 is applied. Selects a signal transmitted from the RCPB and enables the transmission gate 386 by enabling the enable signal En0 .. In this way, the signal generated by the source generator 100 is TSIB through the port A. The signal transmitted from the RCPB is transmitted to the display unit through port B.

On the other hand, since the implementation example of the signal transmission shown in Figure 8d and 8f can be easily understood by those skilled in the art from the above description of the detailed description thereof will be omitted.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited only to the above-described embodiments, and of course, various other modifications and changes are possible.

For example, in the embodiment of the present invention, the IEEE 1394 interface unit includes a port switch having two ports, but may include more than one port switch. In addition, one of the ports of the port switch is a bidirectional port and the other may be implemented as a bidirectional port or two other than the one-way port.

As described above, since the digital television system according to the present invention has a plurality of ports to enable full duplex communication, interactive applications such as PIP or TV phones can be implemented at low cost.

Claims (7)

An antenna for receiving a radio frequency signal transmitted through a digital satellite or airwave; A tuner unit for selecting a desired channel among the signals received from the antenna; A demultiplexer for separating an audio signal and a video signal from a signal output from the tuner unit; An audio decoder for decoding the audio signal separated by the demultiplexer and outputting the decoded audio signal to a speaker; A video decoder for decoding a video signal separated by the demultiplexer and outputting the decoded video signal to a display; And Interfaces the demultiplexer and an IEEE 1394 cable, and transmits a signal selected by the tuner unit and a first port for transmitting a signal received from the outside through the IEEE 1394 cable to the audio decoder or the video decoder to the IEEE cable. IEEE 1394 interface device having a second port for Digital television system comprising a. The method of claim 1, The IEEE 1394 interface device A receiver for receiving an isochronous signal from the IEEE 1394 cable having a time stamp indicating the position information of packet data; A cycle monitor for monitoring timing of a signal received by the receiver; A repair packet block for analyzing the time stamp information of the received isochronous signal and recovering the positional shift of the packet data generated during transmission; A port having the first port for transmitting an isochronous signal recovered by the repair packet block to the demultiplexer and the second port for receiving an isochronous signal selected by the tuner unit through the demultiplexer switch; A time stamp insertion block for adding a time stamp indicating a location of packet data of an isochronous signal selected by the tuner unit received from the port switch, to the isochronous signal; A cycle timer for synchronizing timing of isochronous signals formed by the time stamp insertion block based on a monitoring result of the cycle monitor; And Transmitter for transmitting isochronous signal synchronized with the timing timer by the cycle timer to the IEEE 1394 cable Digital television system comprising a. The method of claim 2, And the first port of the port switch is a bidirectional port capable of receiving isochronous signals selected by the tuner section. The method of claim 3, A first buffer for temporarily storing an isochronous signal received from the receiver, and a second buffer for temporarily storing an isochronous signal selected by the tuner section received from the port switch. . The method of claim 4, wherein And a CRC checker for checking an error of the isochronous signal received from the IEEE 1394 cable and adding a CRC code for error checking to the isochronous signal transmitted from the transmitter. The method of claim 5, And an interface for interfacing the receiver and transmitter with the IEEE 1394 cable. The method of claim 3, The port switch is A first AND gate to which an isochronous signal received from the repair packet block is applied to a first input terminal, and a first enable signal is applied to a second input terminal; A first transmission gate to which an output signal of the first AND gate is applied as an input, an output signal is applied to the first port, and whether to be transmitted by a second enable signal is determined; A buffer configured to apply an isochronous signal generated by the source generator through the first port; A second AND gate to which an output of the buffer is applied to a first input terminal, the first enable signal is applied to a second input terminal, and an output signal is applied to the time stamp insertion block; A multiplexer for selecting one of an output signal of the first buffer and a signal from the repair packet block; And A second transmission gate to which an output signal of the multiplexer is applied as an input, an output signal is applied to the second port, and whether to be transmitted by a third enable signal Digital television system comprising a.