Patent ID: 7688325

Claim:
A method for configuring a graphics processing unit to refresh a screen display using data stored in a local memory or a main memory, the method comprising: setting a threshold limit for a threshold counter to determine whether to store display data in the local memory; generating frames of display data using display data stored in only the main memory when the threshold counter is less than the threshold limit; incrementing the threshold counter upon a refresh of the screen display that does not result in data changes to the screen display; generating a portion of a frame corresponding to one display block of a plurality of display blocks of the screen display using compressed display data stored in the local memory when the threshold limit has been reached and a state bit corresponding to the display block has been set, wherein the state bit is one state bit of a plurality of state bits, each state bit corresponding to a different one of the display blocks of the plurality of display blocks; and generating a second portion of the frame corresponding to a second display block of the screen display using display data stored in the main memory when the threshold limit has been reached and the state bit corresponding to the second display block has not been set.