A method of controlling a display panel which performs a scan operation on an image frame with a first scan setting and a second scan setting includes steps of: outputting a start pulse to the display panel when starting the scan operation; outputting a clock signal to the display panel when the scan operation is in the first scan setting; stopping outputting the clock signal to the display panel when the scan operation is in the second scan setting; and restarting to output the clock signal to the display panel when the scan operation is switched to the first scan setting from the second scan setting. The first scan setting and the second scan setting are for display of the display panel.