Data processing device, data driving device, and system for driving display device using two communication lines

1. A data processing device comprising:

a controlling unit configured to process image data;

a first communication unit configured to include the image data in a first communication signal with a first clock embedded therein and to transmit the first communication signal to a data driving device through a first communication line; and

a second communication unit configured to check a training state of the first clock by the data driving device through a second communication line, and to transmit and receive at least some information to and from the data driving device through the second communication line, wherein the second communication unit comprises a transmission module configured to transmit a signal to the second communication line, a reception module configured to receive a signal from the second communication line, and a monitoring module configured to compare a TX signal transmitted by the transmission module with an RX signal received by the reception module and to generate an error when the TX signal and the RX signal are different,

wherein, when the second communication unit generates the error, the first communication unit performs a clock recovery sequence for retraining the first clock.

2. The data processing device of claim 1 , wherein the second communication line comprises of a common bus of a single signal line and is connected with a plurality of data driving devices.

3. The data processing device of claim 2 , wherein a pull-up resistor is connected to the second communication line, and the second communication unit controls a signal voltage of the second communication line through a switch controlling a connection of the second communication line with a low voltage source.

4. The data processing device of claim 1 , wherein the first communication line is a differential signal line driven by a current, the second communication line is a single signal line driven as an open drain, and the data rate of the first communication line is higher than the data rate of the second communication line.

5. The data processing device of claim 1 , wherein the second communication unit transmits at least some of configuration information to the data driving device through the second communication line in an initial time after an operation is started, and the first communication unit transmits a training signal for the first clock to the data driving device after the at least some of configuration information is transmitted.

6. The data processing device of claim 5 , wherein the first communication unit transmits the training signal for the first clock when a first signal level of voltage is formed in the second communication line by the data driving device after the at least some of the configuration information is transmitted, and determines that a training of the first clock by the data driving device is completed when a second signal level of voltage is formed in the second communication line by the data driving device after the training signal for the first clock is transmitted.

7. The data processing device of claim 1 , wherein the second communication unit transmits a state check command to check a state of the data driving device through the second communication line in an initial time after an operation is started, and determines that the data driving device normally operates when a first signal level of voltage is maintained in the second communication line for a predetermined time or longer by the data driving device after transmitting the state check command.

8. The data processing device of claim 1 , wherein the second communication unit transmits a request command to the data driving device through the second communication line in a time period in which the image data is transmitted through the first communication line, and receives reply data to the request command from the data driving device through the second communication line after transmitting the request command.

9. The data processing device of claim 8 , wherein the request command includes an identification number of the data driving device set by a plurality of pins.

10. A data driving device comprising:

a first communication unit configured to restore a first clock from a first communication signal received through a first communication line and to receive image data included in the first communication signal from a data processing device according to the first clock;

a second communication unit configured to transmit a training state of the first clock to the data processing device through a second communication line and to transmit and receive at least some information to and from the data processing device through the second communication line; and

a controlling unit configured to drive a pixel disposed on a panel according to the image data,

wherein the second communication unit comprises a transmission module configured to transmit a signal to the second communication line, a reception module configured to receive a signal from the second communication line, and a monitoring module configured to compare a TX signal transmitted by the transmission module with an RX signal received by the reception module and to generate an error when the TX signal and the RX signal are different,

wherein when the error is generated, the transmission module adjusts a voltage of the second communication line to a first signal level.

11. The data driving device of claim 10 , wherein the second communication unit operates in a lock mode for transmitting the training state of the first clock and in a communication mode for transmitting and receiving the at least some information.

12. The data driving device of claim 11 , wherein the communication mode is divided into a reception mode and a transmission mode, and

after a second signal level of voltage is maintained in the second communication line for a predetermined time in the reception mode, the second communication unit changes its mode from the reception mode to the transmission mode or the lock mode.

13. The data driving device of claim 11 , wherein the controlling unit checks an identification number set by a plurality of pins, and

the second communication unit processes only a signal corresponding to the identification number among signals received from the data processing device in the communication mode.

14. The data driving device of claim 10 , wherein the second communication unit receives at least some of configuration information from the data processing device through the second communication line in an initial time after an operation is started, and

the controlling unit sets some internal parameters according to the at least some of configuration information before receiving a training signal for the first clock.