The common signal meaning of LED display

1. The CLK clock signal. Provide shift pulse of the shift register. Each pulse will cause data into or out of a place. Data on the mouth must be coordinated with the clock signal to transmit data properly. The frequency of the data signal must be 1/2 times of the frequency of the clock signal. In any case, when the clock signal is abnormal, the whole board display will mess.
2. STB latch signal: The data within the shift register to the latch. And the data content through the drive circuit, then light LED display. But as a result of driving circuit controlled by EN enable signal, the premise of the light must be made to open. Latch signal also need to coordinate with the clock signal to show the complete picture.
3. EN enable signal: The whole screen brightness control signals, also used to display blanking.
As long as adjust its duty ratio can control the change of the brightness. When the enable signal is abnormal, the whole screen will appear not bright, dark bright or trailing phenomenon.
4. The data signal, provide display data for show image. It must be coordinated with the clock signal. Usually red, green and blue in the display of data signal separation. If a data signal is short circuit to the positive or negative, the corresponding to the color will be all bright or not bright. When data signals are dangling, corresponding color is undefined.
5. The ABCD line signal. Only exist in a dynamic scanning display. ABCD is a binary number.
A is the lowest, If use binary representation ABCD signal control maximum range is 16 line.
As long as AB signal can be 1/4 scan, because the scope of AB signal is 4 lines. When the line of control signal is abnormal, there will display dislocate and highlighting or image overlaps phenomenon.