Audio Processing System Based On ARM9

The paper mainly researches the 32-bit high-powered ARM9 embedded processor and the audio coder-decoder chip with high timbre. And an audio processing system based on ARM9 is constructed not only in hardware but also in software, which has technologic and practical values.The system takes the Samsung Ltd S3C2410 processor which based on ARM9 architecture as the main control unit, takes Philips Ltd UDA1380 as the audio coder-decoder processing unit. Being added external memory and keyboard, the system realizes to transmit control signal and audio data by IIC and IIS bus. Basing on WAV audio file, the basic functions which contain recording, playback and synchronous recording and playback are realized. At the same time, the keyboard used as input terminal realizes pause, mute, volume, and tone functions. In order to play MP3 audio file, madplay is ported on development board. The design of system gains the high cost performance ratio, and it also can be applied to multimedia devices such as vehicle sound, portable media player, 3G mobile phone and so on. Especially, that combining the synchronizing record and playback realized in this paper with the Bluetooth technology studied in the next step makes the system effective in many aspects such as monitor and talk-back fields.First of all, the embedded system and the ARM architecture are researched and introduced, and the choice of hardware and software is discussed. Also the design of system is specified. Secondly, the basic hardware platform is constructed and cross development environment is built. Then. the Linux kernel is ported. Thirdly, basing on the driver of UDA1341 which is supplied by Linux2.4 kernel, this paper deeply researches the working theory and programming thought of the DSP and Mixer. It is emphased on designing and developing the audio drivers of UDA1380, IIC-Bus and keyboard. Based. on system transfer function supplied by audio drivers, the program in user application layer is designed to realize the basic and appending function of the system. Finally, after the system testing, with drivers ported in Linux kernel and application programs loaded into file system successfully, the whole design is finished.