An increasing number of the electronic devices we use every day come pre-fitted with displays. As this trend will continues it is easy to see that in the future, hardly any device will be without graphical user guidance.
Even with today's resolutions and depths of color, microcontrollers are not capable of drawing a modern GUI or map (see example below).
Figure 1: PND example
To achieve a better overall system performance, graphics rendering should be transferred from the microcontroller. In the case of the TMS320DM644x, this is from the ARM to the DSP, which, thanks to its flexible DMA channels, is an ideal Soft Graphics Accelerator (SGA). This article gives an insight into why certain graphical algorithms and software architectures were chosen for SGA development.
The principal reason for using the DSP instead of an external Hardware Graphics Accelerator (GPU) lies in the significant cost saving. The TSM320DM644x already has a display controller and a fast connection to main memory. In most cases, a GPU will need an additional, dedicated memory. Considerable extra cost is involved in these two additional chips, which could be saved with an SGA.
Figure 2: General HW architecture
Figure 3: DaVinci HW Architecture
Next: General DaVinci software architecture