1. Field
Embodiments of the invention relate to the field of display systems, and more specifically, to an apparatus and method for retrieving display data from an internal frame buffer and an external frame buffer.
2. Background
Portable devices may employ an internal frame buffer that is embedded within a graphics chip to store display data. However, due to cost of providing a large internal memory array within the graphics chip, the internal memory array is typically not large enough to contain more than one buffer, which may be needed for implementing double buffered graphics or multimedia performance model techniques. In double buffering, two frame buffers are provided instead of a single frame buffer. In this regard, the display system can write pixel data into one frame buffer while the display shows pixel data previously written into the other frame buffer. In some prior art systems, one frame buffer (i.e., internal frame buffer) will be located internally within the graphics chip, while the other frame buffer (i.e., external frame buffer) is located outside the graphics chip. In some prior art system, the display controller implementing double buffering may alternate between refreshing the display from the internal frame buffer and the external frame buffer.