Design Of USB Audio System

The criterion of USB Universal Serial BUS Interface was established by Intel associate with other 6 computer and cummunication manufacturers in 1995. The USB interface have beacame the developmental trend of modern date transport gradually for the advantages of convenience for installation, high bandwidtheasily to be extended and hot insert and pull out support.Compared with the widely used equipment presently, such as computer terminal audio unit,sound box and earphone, USB Audio System have the advantages of simplified connection, self-support power supply. It is discovered by investigation that there are few USB audio equipment in the market at present, the USB interface is merely used for power supply if there is any. It is discovered by investigation that there are few USB audio equipment in the market at present, the USB interface is merely used for power supply if there is any. Nevertheless, USB BUS of the USB Audio System in this paper is used for transport medium of power and audio data.This article firstly analyse the USB Audio System entirely, including MCU software core, USB equipment controller and introduction of function of D type power amplifier and the correlation of each other. The next is the essential of this article -- design and realization of USB controller, including introduction of USB protocol and concretely realization of USB controller, further more, this article validates the function of USB controller, and discusses the design and realization of D type power amplifier. When hardware construction finished, the article discusses the development of hardware, at the end of the article is the outcome and appraisal of systemic grade validity of USB Audio System. The following is the work this theme finished and the achievement it reached:Firstly, the theme designs a USB audio system chip which based the USB controller. The chip can connect with the USB interface of PC directly without driver. It is convenient to realize audio files playing. Obverse design method is used in design process. The design process consists of system function structural dividing, definition of module function, I/O port definition, functional RTL description as well as custom design of analog module.secondly, the applicational hardware has been developed aiming at the USB audio system, mainly finished the communication with USB host computer, the operation to the system via external port and system configuration.thirdly, currently, in the design procession of integrate circuit, validation costs almost 70% of the design period. According to demand of designation, the validation platform is built, and FPGA simulation validation is processed, and the result of validation satisfy the demand of designation. finally, I designed the layout of the entire chip, processed the simulation with parasite parameters, and procured satisfying performance index.