Patent ID: 6441812
Filing Date: 2002-08-27
Classification: G09G,H04N

Abstract:
A system for displaying graphics data on a display device, the system comprising:a graphics controller for the outputting graphics data to be displayed on the display device and the graphics controller further for outputting a first synchronization signal having a first frequency, the first synchronization signal being outputted from the graphics controller to the display device; a secondary source of video data available to the graphics controller; a genlock unit for outputting a clock signal to the graphics controller and for receiving as a feedback input the first synchronization signal output by the graphics controller, the genlock unit also for receiving a second synchronization signal associated with the secondary source of video data, the second synchronization signal having a second frequency different from the first frequency; and a graphics memory connected to the graphics controller, the graphics memory responsive to the clock signal output by the genlock unit; wherein the genlock unit is configured to generate the clock signal at the frequency of the second frequency based on a comparison of the first synchronization signal with the second synchronization signal, wherein the clock signal frequency is generated based on the phase difference between the first synchronization signal and the second synchronization signal and wherein the graphics controller is configured to generate the first synchronization signal outputted to the display device responsive to the clock signal frequency generated by the genlock unit.