METHOD AND APPARATUS FOR CONTROLLING SPARSE REFRESH OF A SELF-REFRESHING DISPLAY DEVICE COUPLED TO A GRAPHICS CONTROLLER

A method and apparatus for controlling sparse refresh of a self-refreshing display device coupled to a graphics controller are disclosed. The display device includes capabilities to drive the display based on video signals generated from a local frame buffer. The graphics controller may optimally be placed in one or more power-saving states when the display device is operating in a panel self-refresh mode. When exiting the power-saving state to update the image displayed by the display device, a fast-resume initialization routine may be run to reconfigure the GPU when operating in a sparse refresh mode, i.e., where the image being displayed on the display device is updated infrequently. In such cases, the graphics controller may be configured to receive instructions and data from a central processing unit via an alternative low-bandwidth communications path instead of the high-bandwidth communications path used in normal operation.