Apply Hardware Accelerator In Embedded Multimedia System

The rapid development of consumer mobile electric products requires higher performance of embedded multimedia system. Achieving the higher requirement, more and more embedded multimedia systems need to support high speed and performance graphic system. So it's the opportunity that the embedded hardware graphic accelerators shows the value, and gradually accepted by modern high-end embedded systems.This paper focus on a embedded application platform based on ARM architecture, studying how to apply 2D hardware graphic accelerator in this platform, including setting up the embedded operating system, designing and implementation of the device driver and non-standard graphic library and 2D graphic benchmark. The key points are effective design and implementation for embedded device drivers, good user interface and graphic function library. This paper mainly concerns on the following work:Designed a self-adaptive software-hardware instruction cooperate architecture. This architecture has developed a software-hardware integrated instruction executing system. It turns software graphic instructions to a familiar structure as hardware graphic instructions, so it gets the same instruction interface for both software and hardware instructions. It also makes use of a"waiting for event"interrupt, and achieves software-hardware instruction executing seamlessly. Therefore it can hide the hardware details, and keep the correct order of the instruction at the same time.Posted a buffer submit strategy which bases on total instructions cost. It sets up the instruction execute cost model first, then gets the main parameters by a lot of experimental data. Applying this strategy, it decides the time to submit instruction buffer with consideration of the estimated total instruction execute time combined with the system timer. It makes good effect on both hiding the hardware detail and improve the response in heavy render tasks.The paper provides a hardware device support suite of embedded Linux system on the PXA300 platform, including device drivers and a private graphic lib. Besides, it tests the performance of integrated hardware 2D graphic accelerator with 2D graphic benchmark program.The result shows that the graphic performance has been great improved. It tells that the speed of graphic rendering is increased by 8– 20 times. And it saves the power by reduce the CPU percentage(bellow 20% of CPU) while keeping a friendly user programming interface. So, we got a conclusion that hardware accelerators are available and valuable for embedded multimedia system, and they have great potential in future.