Display driver integrated circuit and display data processing method thereof

A display driver integrated circuit according to the present invention comprises a first line buffer which receives a first pixel data of odd-numbers in response to an external clock and outputs the first pixel data corresponding to an internal clock, a second line buffer which receives a second pixel data of even-numbers in response to the external clock and outputs the second pixel data corresponding to the internal clock, a line buffer controller which receives display data of two pixel data units to output the first and the second pixel data, a data merging device which converges the first pixel data output from the first line buffer and the second pixel data output from the second line buffer, and an image data processing block that processes the merged pixel data, and the frequency of the internal clock is slower than that of the external clock.