A source driver control device and method. The source driver control device includes a memory, a first write controller, a second write controller and a write clock signal generator. The memory receives display data corresponding to an image and stores the display data in response to a write clock signal. The first write controller generates a first write enable signal in response to a vertical back porch and a horizontal back porch. The second write controller generates a second write enable signal, which is enabled for each write cycle of storing the display data in the memory, in response to the first write enable signal. The write clock signal generator generates the write clock signal in a period in which the second write enable signal is enabled. The write cycle corresponds to a multiple of a reference write cycle. The source driver control device and method can reduce power consumed when the display data is written in the memory.