A processor for use in an electronic device is provided. The electronic device is capable of displaying and the processor has capability of switching a refresh rate for refreshing a display panel of the display device. The processor comprises: a refresh rate selection controller and a display controller. The refresh rate selection controller is configured to dynamically select one from a plurality refresh rates. The display controller is configured to control a driving device to refresh the display panel with the selected refresh rate and determine whether to adjust a data transmission rate over an interface between the processor and the driving device according to the selected refresh rate.