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:

• generating a clock turn-off signal when the main drive control chip recognizes that its operating frequency is unstable;
• transmitting fixed data to each of the plurality of column drive control chips according to the clock turn-off signal and receiving a clock training request initiated by said each of the plurality of 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 front-end data transmitted by the front-end motherboard chip, responding to the clock training request and transmitting clock training data to said each of the plurality of 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 including a plurality of column drive control chips, the method comprising:

• generating a clock turn-off signal when the pre-stage communication apparatus recognizes that its operating frequency is unstable;
• transmitting fixed data to each of the plurality of post-stage communication apparatuses according to the clock turn-off signal, and receiving a clock training request initiated by said each of the plurality of post-stage communication apparatuses according to the fixed data;
• and
• when recognizing that the operating frequency synchronizes with a frequency corresponding to received front-end data, responding to the clock training request and transmitting clock training data to said each of the plurality of post-stage communication apparatuses.