Controlling device and method for frequency synchronization and lcd television

A controlling method for frequency synchronization, applied to a LCD TV, wherein the LCD TV comprises a front-end motherboard chip, a main drive control chip and a plurality of column drive control chips, the method comprises:

• when the main drive control chip recognizes that its operating frequency is unstable, it generates a clock turn-off signal;
• the main drive control chip transmits fixed data to each of the column drive control chips according to the clock turn-off signal and receives a clock training request initiated by each of the column drive control chips according to the fixed data;
• and
• when the main drive control chip recognizes that the operating frequency synchronizes with a frequency corresponding to the front-end data transmitted by the front-end motherboard chip, the main drive control chip responds to the clock training request and transmits clock training data to each of the column drive control chips.

A controlling method for frequency synchronization, applied to a point-to-point communication system, wherein the point-to-point communication system comprises a pre-stage communication apparatus and a plurality of post-stage communication apparatuses, the method comprising:

• when the pre-stage communication apparatus recognizes that its operating frequency is unstable, it generates a clock turn-off signal;
• the pre-stage communication apparatus transmits fixed data to each of the post-stage communication apparatuses according to the clock turn-off signal, and receives a clock training request initiated by each of the post-stage communication apparatuses according to the fixed data;
• and
• when recognizing that the operating frequency synchronizes with a frequency corresponding to the received front-end data, the pre-stage communication apparatus responds to the clock training request and transmits clock training data to each of the post-stage communication apparatuses.