Research And Realization Of Embedded USB-HOST

Data exchange and storage for mobile devices has been the hotspot of IT world for several years. Mobile and convenient data exchange builds up the base of digital world. Mobile data exchange excites the development of IT, and brings convenience to peoples' lives.USB was put forward to patch up all kinds of shortages of traditional buses. USB has been used widely in data exchange and storage of PC area because of its characteristics of relative high speed, easiness of installing, connecting and expanding, support of "plug and play", relative less requirement of resources. People show more and more expectation as USB expands its applications. They hope that USB can be used without PC host, that is, PDA and digital cameras can communicate with USB peripheral directly. The research of embedded USB host system agrees the development of IT industry. It takes a further step in mobile and convenient data exchange in the meaning of practicality.This article shows the research and understands on the whole USB framdwork. It describes the USB firmware implimentation for digital camera applications, including the USB OHCI core driver, USB mass storage device driver, USB printing device driver, USB virtual serial port device driver.The theory and technology of embedded USB host system are highlights in the article. In chapter 2, it researches the whole USB protocol as well as framework. In chapter 3, it compares the characteristics of PC and embedded system and brings up the methord to customize, to simplify and to cutting for embedded USB host system. In chapter 5, it describes the USB protocol analyze and USB host coding in MPIX 113 SDK, including USB OHCI driver, USB MSC driver, USB printer driver and USB virtual serial port driver.