METHOD AND APPARATUS FOR SYNCHRONIZING GRAPHICS PIPELINES
摘要
<p>A method and apparatus for synchronizing the execution of a sequence of graphics pipelines is provided. For a representative embodiment a sequence of graphics pipelines are connected in a daisy-chain sequence. Each pipeline operation can be controlled to operated in one of two modes. The first is a local mode where the pipeline outputs its own digital video data. The second is a pass-through mode where the pipeline outputs digital video data received from preceding graphics pipelines. The pipelines are configured to allow an application executing on a host process to select the next pipeline that will enter local mode operation. The pipeline that is selected to enter local mode operation asserts a local ready signal when it is ready to begin outputting its digital video information. Each of the pipelines monitors the state of a global ready signal. When the global ready signal becomes asserted it means that the pipeline that is selected to enter local mode operation is ready. It also means that all other pipelines that are configured to work in parallel with the sequence of pipelines are ready. At this time, selected the selected pipeline enters local mode operation. The remaining pipelines in the sequence either enter or remain in pass-through mode operation.</p>
