CN101150689B

CN101150689B - Method and circuit for realizing LCD TV VGA arousing function

Info

Publication number: CN101150689B
Application number: CN200710124084XA
Authority: CN
Inventors: 孔令枝; 黄运汉; 周波; 汪繁
Original assignee: Konka Group Co Ltd
Current assignee: Konka Group Co Ltd
Priority date: 2007-10-25
Filing date: 2007-10-25
Publication date: 2011-05-25
Anticipated expiration: 2027-10-25
Also published as: CN101150689A

Abstract

A method for realzing VGA arousing function of liquid crystal television and a circuit thereof, wherein the method comprises: according to characteristics of VGA terminal nine-pin voltage changing from low to high when a VGA is output, adopting an external circuit, generating a low electric level pulse with adjustable pulse width at will, a main chip I/O can arouse VGA of a liquid crystal television and a display through detecting the low electric level pulse; the circuit comprises XS1 which is used as a VGA interface, one I/O interface which uses Detect as the main IC, using VCC as a power source; when a VGA signal is output, 9 pin A point electric level nine-pin A point electrical level of the VGA termial is changed from low (0V) to high (5V), a low electric level pulse is formed through the circuit B point, once the low electric level pulse is detected by the I/O interface Detect, the VGA function of the system is aroused. The detecting pin Detect does not occupy a new I/O interface of the main chip through multiplexed key input port key; the method does not need the main chip reading registers and detecting VGA line-field synchronously, does not need ADC power supply, which uses characteristics of VGA terminal nine-pin voltage changing from low to high when a VGA is output to realize VGA arousing function of liquid crystal televisions and display products.

Description

The implementation method of LCD TV VGA arousing function and circuit thereof

Technical field

The present invention relates to the awakening method of LCD TV, the implementation method and the VGA wake-up circuit of particularly a kind of liquid crystal indicator VGA arousal function during as display.

Background technology

The VGA arousal function of existing LCD TV, display product, often realize in the following ways: see among Fig. 1, ADC POWER is the ADC power supply of master chip, the line synchronizing signal (VGA_HSYNC) of register 1 access VGA, the field sync signal (VGA_VSYNC) of register 2 access VGA.During system standby, master chip MCU reads a row buffer status in each main circulating program cycle and judges the row field sync signal by complicated software algorithm, in case detect the capable field sync signal of VGA, wakes the VGA function of display at once up.Because existing VGA arousal function is under the system standby state, master chip MCU detects constantly that the capable field synchronization of VGA signal realizes, when this just required the display standby, the ADC power supply of chip can't power down, had increased the stand-by power consumption of system; And program is in running, and the register of continual access line field synchronization causes master chip MCU can not enter standby dormancy low power consumpting state, has expended certain system resource.

Summary of the invention

The implementation method and the circuit thereof that the purpose of this invention is to provide a kind of LCD TV VGA arousing function, realize the VGA arousal function of LCD TV, display product by increasing a peripheral circuit, and the permission system closes ADC power supply, SCALE chip power under holding state, thereby effectively reduce the stand-by power consumption of system, overcome the deficiency that available liquid crystal TV awakening method exists preferably.

Realize that method of the present invention is: when described method has been included in VGA output, VGA terminal 9 pin voltages are from the low characteristic that uprises, adopt a kind of peripheral circuit, produce the low level pulse that pulsewidth can be regulated arbitrarily, master chip I/O mouth is realized the VGA arousal function of LCD TV, display by detecting this low level pulse.

This method also comprises: will produce the be added to button input port KEY of LCD TV, display of low level pulse waveform that pulsewidth can regulate arbitrarily is on chip I/O mouth, when pressing, button produces waveform by regulating the simulation of low level pulse width, as long as detect increase by one road VGA wake-up level detecting on the framework in former software keys, under the prerequisite that need not newly-increased I/O mouth, just can realize the VGA arousal function of LCD TV, display by multiplexing button input port KEY.

Realize that wake-up circuit of the present invention is: 9 pin of VGA terminal are ground connection behind resistance R 2 connecting resistance R3, and resistance R 3 is in parallel with capacitor C 1; Connect the base stage of triode V1 between resistance R 2 and the resistance R 3 through resistance R 1,9 pin of VGA terminal connect the collector electrode of triode V1, the grounded emitter of triode V1 through resistance R 5; Cross-over connection resistance R 4 between the collector electrode of the base stage of triode V2 and triode V1, the grounded emitter of triode V2, the collector electrode of triode V2 meets VCC through resistance R 6; The collector electrode of resistance R 7 one termination triode V2, the other end connects the I/O mouth of master chip MCU respectively, through capacitor C 2 ground connection.

The invention has the beneficial effects as follows: the stand-by power consumption that 1, effectively reduces system; 2, saved the system resource of program; 3, the VGA wake-up circuit is realized simple, reliable; 4, chip I/O mouth is multiplexing, has saved system resource effectively.

Description of drawings

Fig. 1 is a schematic diagram of realizing the VGA arousal function in the prior art.

Fig. 2 is VGA arousal function circuit theory diagrams of the present invention.

Fig. 3 is that the present invention detects pin Detect by multiplexing button input port key, increases the FB(flow block) of one road VGA wake-up level detecting.

Embodiment

The present invention has used cleverly when VGA output is arranged, and VGA terminal 9 pin voltages adopt a kind of peripheral circuit of simple maturation, shown in figure (2) from the low characteristic that uprises.Wherein XS1 is the VGA interface; Detect is one of them I/O mouth of main IC; VCC is an electric power network; When the VGA signal was exported, 9 pin A level points of VGA terminal will uprise (5V) from low (0V), and in the moment of level saltus step, C1 begins to be recharged, and triode V1 ends, triode V2 conducting, and the B level point is dragged down; Treat that the C1 charging finishes, triode V1 base voltage is high, the V1 conducting, and triode V2 ends, and the B level point reverts to height; The B point just forms a low level pulse like this, and in a single day I/O mouth Detect detects this low level pulse, at once the VGA function of waken system.Its pulse duration can arbitrarily be chosen by adjusting the RC parameter.

The present invention another cleverly usage be, with producing the be added to button input port KEY of LCD TV, display of low level pulse waveform that pulsewidth can regulate arbitrarily is chip I/O mouth, when pressing, button produces waveform by regulating the simulation of low level pulse width, as long as detect increase by one road VGA wake-up level detecting (as shown in Figure 3) on the framework, just can realize the VGA arousal function of LCD TV, display product in former software keys.Detect pin Detect like this and need not take the new I/O mouth of master chip in addition by key control mouth key, effectively saved system resource by multiplexing.

This circuit is realized simple, and is reliable.Need not the master chip capable field synchronization of reading registers and detecting VGA repeatedly, and need not the ADC power supply, used cleverly when the output of VGA signal is arranged, VGA terminal 9 pin voltages are realized the VGA arousal function of LCD TV, display product from the low characteristic that uprises.

Referring to Fig. 2,9 pin (2) of VGA interface (1) are ground connection behind resistance R 2 connecting resistance R3, and resistance R 3 is in parallel with capacitor C 1; Connect the base stage of triode V1 between resistance R 2 and the resistance R 3 through resistance R 1,9 pin (2) of VGA interface (1) connect the collector electrode of triode V1, the grounded emitter of triode V1 through resistance R 5; Cross-over connection resistance R 4 between the collector electrode of the base stage of triode V2 and triode V1, the grounded emitter of triode V2, the collector electrode of triode V2 meets electric power network VCC through resistance R 6; The collector electrode of resistance R 7 one termination triode V2, the other end meet the I/O mouth Detect of master chip MCU respectively, through capacitor C 2 ground connection.When the VGA signal was exported, 9 pin (2) the A level point of VGA interface (1) will uprise (5V) from low (0V), and in the moment of level saltus step, C1 begins to be recharged, and triode V1 ends, triode V2 conducting, and the B level point is dragged down; Treat that the C1 charging finishes, triode V1 base voltage is high, the V1 conducting, and triode V2 ends, and the B level point reverts to height; The B point just forms a low level pulse like this.In a single day the I/O mouth Detect of master chip MCU detects this low level pulse, at once the VGA function of waken system.Its pulse duration can arbitrarily be chosen by adjusting the RC parameter.VGA interface (1) is XS1.Triode is BC847.

Referring to Fig. 3, this is an another embodiment of the present invention, promptly detects the I/O mouth that pin Detect does not take master chip, but detects by multiplexing button input port key.The be added to button input port key mouth of LCD TV, display of the low level pulse waveform that B among the last embodiment is ordered, when pressing, button produces waveform by regulating the simulation of low level pulse width, detect in existing software keys on (standby key level and other button level detection) framework and increase the detecting of one road VGA wake-up level, in a single day the KEY mouth detects the low level pulse that B is ordered, and wakes the VGA function of LCD TV, display product system at once up.

Above-mentioned described execution mode is preferred embodiment, but the invention is not restricted to above-mentioned specific embodiment, and some identical or replacement schemes that those of ordinary skill in the art can expect apparently all should fall into the scope that invention is protected.

Claims

1. the implementation method of a LCD TV VGA arousing function, when comprising system standby, master chip MCU realizes the arousal function of display by the capable field synchronization of continuous detection VGA signal, when it is characterized in that described method has been included in VGA output, according to VGA terminal supportor voltage from the low characteristic that uprises, adopt a kind of peripheral circuit, produce the low level pulse that pulsewidth can be regulated arbitrarily, master chip I/O mouth realizes that by detecting this low level pulse the VGA of LCD TV, display wakes up;

In described peripheral circuit, 9 pin of described VGA terminal ground connection after second resistance connects the 3rd resistance, the 3rd resistance is in parallel with first electric capacity; Connect the base stage of first triode between second resistance and the 3rd resistance through first resistance, 9 pin of VGA terminal connect the collector electrode of first triode, the grounded emitter of first triode through the 5th resistance; Cross-over connection the 4th resistance between the collector electrode of the base stage of second triode and first triode, the grounded emitter of second triode, the collector electrode of second triode meets electric power network VCC through the 6th resistance; The collector electrode of the 7th resistance one termination second triode, the other end is the B point, this B point connects the I/O mouth of master chip MCU respectively, through second capacity earth;

When the VGA signal was exported, 9 pin level of VGA interface will become high level 5V from low level 0V, and in the moment of level saltus step, first electric capacity begins to be recharged, and first triode ends, the second triode conducting, and the B level point is dragged down; Treat that the charging of first electric capacity finishes, the first transistor base voltage is high, the first triode conducting, and second triode ends, and the B level point reverts to height; The B point just forms a low level pulse like this, and its pulse duration can arbitrarily be chosen by adjusting the RC parameter.

2. the implementation method of LCD TV VGA arousing function as claimed in claim 1, it is characterized in that it is chip ADC sampled I/O mouth button by the key control mouth that described method also comprises what produce that low level pulse waveform that pulsewidth can regulate arbitrarily is added to LCD TV, display, when button is pressed, produce waveform by regulating the simulation of low level pulse width, and detect in former software keys and to increase by one road VGA wake-up level on the framework and detect the VGA that realizes LCD TV, display and wake up.