JP2684626B2 - Data transmission method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a data transmission system, and more particularly to a system for displaying an output of a parallel output port of a decoder.

[Prior Art] In general, a display device may display a decoder output state by directly connecting a display element to a decoder output, or may display a decoder output by processing it through a microprocessor.

FIG. 3 is a circuit diagram showing a conventional data transmission type display device already commercialized, for example, in a color television set CT-2553STX manufactured by Mitsubishi Electric Corporation.
(1) is a decoder IC for digital audio multiplex broadcasting (hereinafter, referred to as digital broadcasting), which has an output port (1a) for displaying the stereo mode of the digital broadcasting and an output port (for displaying one mode of two languages of the digital broadcasting). 1b), output port (1c) that displays bilingual 2 modes of digital broadcasting, output port (1d) that displays whether the audio of digital broadcasting matches the video or independent audio that is not related to the video, power supply terminal (1e) and a ground terminal (1f).

(2) is a display circuit for displaying the mode of digital broadcasting, and has light emitting diodes (LED) (2a) to (2d) corresponding to the output ports (1a) to (1d). (3) is a resistor circuit, which is a pull-up resistor (3a)-(3) connected in series to each of the LEDs (2a)-(2d).
It consists of d).

 Next, the operation of the above configuration will be described.

The decoder IC (1) receives digital broadcast encoded data as input, reformats it, and outputs data for digital-to-analog converter, as well as digital broadcast modes (stereo, bilingual, bilingual). It has an output port for displaying the national language 2) and whether the digital broadcast matches the video or whether it is an independent audio that has nothing to do with the video and whether or not the digital broadcast is present. Output ports (1a) to (1d) Has an open drain output.

The operation of the decoder IC (1) will be described with reference to the time chart of FIG.

When the decoder IC (1) receives the audio that matches the video in stereo mode, each output port becomes T1 state,
LED (2a) that indicates stereo mode and match detection LED (2d) from V _DD via pull-up resistors (3a) to (3d)
Is lit up, and LED (2b) that displays Bilingual 1.2 mode,
(2c) is turned off to display that the audio matches the stereo mode and video. Similarly, bilingual 1,2 mode,
When the audio that matches the video is received, each output port is T2
Then, the LEDs (2b) to (2d) are turned on, and the LED (2a) is turned off to indicate that the language is the same as that of the bilingual mode.

Also, when bilingual 1 mode, when audio that matches the video is received, each output port becomes T3 and LED (2
b) and (2d) are turned on, and (2a) and (2c) are turned off to indicate that the audio is in a bilingual 1 mode and matches the video.

In addition, when bilingual 2 mode, when audio that matches the video is received, each output port becomes T4 and LED (2
c) and (2d) are turned on, and (2a) and (2b) are turned off to indicate that the audio is the same as the bilingual 2 mode video.

Also, when receiving a digital broadcast independent of the video, it will be in the state of T5 to T8, and contrary to the audio that matches the above video, the LED (2d) is always turned off and the audio is independent of the video. Is displayed and when audio without digital broadcasting is received, each output port becomes T9 and LED (2a)
All ~ (2d) lights off, indicating that there is no digital broadcasting.

FIG. 5 shows a circuit diagram when the output of the decoder IC (1) is processed and displayed by the microprocessor (4),
In the figure, (1), (1a) to (1f), (3), (3
Since a) to (3d) are the same as those in FIG. 3, the same reference numerals are given and their description is omitted.

In FIG. 5, (4) is a microprocessor, input ports (4a) to (4d) and power supply terminals (1e) corresponding to the output ports (1a) to (1d) of the decoder IC (1), respectively.
Has a power supply terminal (4e) and a grounding terminal (4f). Reference numeral (5) is a display interface, which is connected to the display output port (4g) of the microprocessor (4). (6) is a cathode ray tube which serves as a display element.

[Problems to be Solved by the Invention] Since the conventional data transmission system is configured as described above, when the output of the decoder IC (1) is processed and displayed by the microprocessor (4), it is shown in FIG. As shown, in order to read the output of the decoder IC (1) into the microprocessor (4), four input ports (4a) ...
(4d) is required, a microprocessor (4) with a large number of ports is used, and the number of ports needs to be expanded, which makes the corresponding circuit expensive and large.
There is a drawback that it is restricted to use a display device with a dedicated LED as shown in the figure.

The present invention has been made to solve the above problems, and a display using a microprocessor can realize display with one data input port, and a display element is directly connected to a decoder output. An object of the present invention is to provide a data transmission method that can be compatible with the case of displaying.

[Means for Solving the Problem] A data transmission system according to the present invention has an output port for outputting a plurality of first signals, and outputs a second signal whose repetition cycle is earlier than the first signal described above. A decoder adapted to output to each output port, and to superimpose a second signal from another output port as a serial data on a first signal from one or more of the output ports; A diode connected to one or more output ports for outputting serial data and adapted to obtain an OR output of the serial data, and by connecting display means to a predetermined output port of the decoder, or The output of the decoder can be displayed by connecting a display means using a microprocessor to the output side of the diode. To.

[Operation] According to the present invention, it is possible to output a signal having a fast repetition period to each output port of the decoder, while a first signal from one or a plurality of output ports is repeatedly output from another output port. Outputs serial data while superimposing the second signal with a short cycle as serial data 1
Or, since a diode is connected to a plurality of output ports to take out the OR output, by connecting a display means to a predetermined output port of the decoder or a display means using a microprocessor on the output side of the diode. By connecting, the output of the decoder can be displayed.

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

FIG. 1 is a circuit diagram of a data transmission type display device according to an embodiment of the present invention. In FIG. 1, (1), (1
a) to (1f), (3), (3a), (3b), (5),
Since (6) is the same as the conventional example shown in FIG.
Only parts different from those in the figure will be described.

That is, in FIG. 1, the stereo output port (1
a), Bilingual 1 output port (1b) and V _DD with pull-up resistors (3a) and (3b) respectively connected to the stereo output port (1a) and Bilingual 1 output port (1b) side. The anode side of each diode (7a), (7b) is connected, and the cathode side of each diode (7a), (7b) is connected to the display input port (8a) of the microprocessor (8) as a common output terminal. . In this case, it goes without saying that a clock line (not shown) is provided between the decoder IC (1) and the microprocessor (8) for transmitting a clock signal which serves as a reference for serial data transmission. With such a configuration, with / without digital broadcasting,
Digital broadcasting mode (stereo, bilingual 1, 2, bilingual 1, bilingual 2), it is determined whether the audio matches the video / independent audio, and the display output port (8b) displays the interface ( The respective discrimination inputs are displayed on the cathode ray tube (6) which is a display element via 5).

When the decoder IC (1) is in stereo mode, it outputs stereo information to the bilingual 1 output port (1b), and information that is audio that matches the video is “H” or “L” that has a short repetition cycle and does not affect the lighting of the LED. "It outputs a transmission code composed of signals, and when not in stereo mode, with or without digital broadcasting in the stereo output port (1a), digital broadcasting mode (bilingual 1, 2, bilingual 1, In bilingual language 2), the information from the audio that matches the video / independent audio is output as a signal that does not affect the lighting of the LED in the same manner as above, and also the input port for display (8a) Ground terminal (8
A pull-down resistor (9) is connected between b).

The display device of the data transmission system having the above configuration operates as shown in the time chart of FIG. That is,
Stereo output port (1a) and bilingual 1 output port (1b) with / without digital broadcasting, digital broadcasting mode (stereo, bilingual 1,2, bilingual 1, bilingual 2), match with video Since 9 kinds of combinations of audio / video and independent audio are output as serial data,
The OR logic outputs of the output ports (1a) and (1b) of the book can be displayed by inputting them to the display input port (8a) of the microprocessor (8).

In the above-described embodiment, the signal of the output port of the decoder IC (1) has serial data multiplexed on one of them, but the data may be multiplexed on all output ports (1a) to (1d). .

Further, in the above embodiment, the display element is a cathode ray tube, but a liquid crystal display or the like may be used.

Furthermore, although the audio multiplexed serial data was multiplexed to the output port of the decoder IC (1), the audio mute function and the presence / absence of audio signal data were multiplexed, and the power was automatically turned off after a certain time after the audio signal disappeared. Such a function can also be realized without increasing the number of ports of the microprocessor (8).

[Effects of the Invention] As described above, according to the present invention, a signal with a fast repetition period is output to each output port of a decoder, while a first signal from one or a plurality of output ports is output.
The second signal from another output port, which has a fast repetition cycle, is superimposed as serial data, and a diode is connected to one or more output ports that output serial data to extract the OR output. In addition to being able to display by directly connecting the display means to a predetermined output port of, and by connecting the display means using a microprocessor to the output side of the diode, all information can be displayed at one data input port. Input can be made, and the interface and display element of the display device can be shared with those used for display of other circuits, so that there is an effect that the device can be made compact and inexpensive.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a display device of a data transmission system according to an embodiment of the present invention, FIG. 2 is a time chart in the data transmission system of FIG. 1, and FIG. 3 is a circuit of a display device of a conventional data transmission system. 4 and 5 are time charts in the data transmission system of FIG. 3, and FIG. 5 is a circuit diagram of a display device in the conventional data transmission system realized by the conventional decoder IC. (1) …… decoder IC, (1a) to (1d) …… output port, (8) …… microprocessor, (8a) …… input port, (8b) …… output port. The same reference numerals in the drawings indicate the same or corresponding parts.

Claims (1)

(57) [Claims] 1. A second signal having an output port for outputting a plurality of first signals, wherein a second signal having a repetition cycle faster than that of the first signal can be output to each of the output ports, and Or connected to a decoder adapted to superimpose a second signal from another output port as serial data on a first signal from the plurality of output ports and to one or more output ports for outputting the serial data. And a diode adapted to take out the OR output of the serial data, and connecting a display means to a predetermined output port of the decoder, or a display means using a microprocessor on the output side of the diode. A data transmission system characterized in that the output of the decoder can be displayed by connecting.