Research On Digital Recording Technology Based On USB Host

Since the birth of USB, it has undergone great development and has been applied into a wide range of areas. At present, USB slaves and USB host technology based on PC has achieved great maturity. Meanwhile, the demand of integrating USB host interface in embedded system has become urgent. Because embedded USB host technology has promising future in real-time data sampling and storage fields. This dissertation has done some research on digital recording technology based on USB host. The main work includes implementing USB host function in embedded system based on MCU and storing sampled digital audio on the U-disk through USB host interface to implement digital recording.Firstly, the dissertation gives an introduction of digital recording system's development as well as USB technology and its application. Secondly it focuses on analysis of USB architecture, data communication and framework of USB protocol and proposes a general design for system. It also analyzes the design principles of USB host system's hardware. And USB protocol is implemented on the basis of the analysis of USB host protocol and its software framework. Then Mass Storage class and its subclass UFI command set has been discussed in detail. A part of UFI commands has been implemented to read and write the logic sector of U-disk through Bulk-Only transport protocol, providing an interface for upper file system. Finally, it introduces the design principles of audio sampling circuit based on MC14LC5480. On the basis of the introduction, we have designed and optimized the FAT 16 file system at the implementation level to accomplish the real-time storage of digital audio file on the basis of analysis of FAT 16 file system's structure. The dissertation is ended with the summarization of research work and the prospect of the further research work.