Data driving device, method and system for driving display device

A data driving device comprising:

• a communication circuit configured to receive an image data signal from a data processing device through a first communication line, to receive a state reply command signal from the data processing device while receiving the image data signal, and to process the state reply command signal into state reply command information;
• a lock control circuit configured to output a lock signal of a first level when the communication circuit receives the image data signal;
• and
• a logic gate configured to transmit an operation state signal regarding an operation state of the communication circuit, instead of the lock signal of the first level, through a second communication line connected with an output terminal when receiving the state reply command information from the communication circuit, wherein the second communication line is connected with the data driving device, another data driving device, and the data processing device, and wherein the data driving device, the another data driving device, and the data processing device are connected in series through the second communication line.

A system comprising:

• a first data driving device configured to receive a first image data signal through a 1-1st communication line, to transmit a first lock signal through a 2-1st communication line, and to transmit an operation state signal representing an operation state inside the first data driving device, instead of the first lock signal through the 2-1st communication line, when receiving a state reply command signal while receiving the first image data signal;
• a second data driving device configured to receive a second image data signal through a 1-2nd communication line, to generate a second lock signal, to receive the first lock signal through the 2-1st communication line, to perform a logical operation with respect to the first lock signal and the second lock signal, to transmit a signal obtained by the logical operation through a 2-2nd communication line, to receive the operation state signal through the 2-1st communication line, to perform a logical operation with respect to the operation state signal and the second lock signal, and to transmit a second operation state signal obtained by the logical operation through the 2-2nd communication line;
• and
• a data processing device configured to transmit the first image data signal through the 1-1st communication line, the second image data signal through the 1-2nd communication line, and the state reply command signal through the 1-1st communication line and subsequently to receive the second operation state signal through the 2-2nd communication line.