U Disk Smartphone

USB (Universal Serial Bus) is designed to solve the contradiction between the increasing peripheral devices and the limited interfaces of the main board of computers. It is a kind of outer bus structure which is used to connect the peripheral devices and main boards. Meanwhile, USB is also a communication protocol, which supports the data transaction between USB hosts and USB devices. In a word, USB provides a new kind of standard interface between computers and input/output devices. Features such as electrical detail isolating from end user and dynamically attachable and reconfigurable peripherals make it easier to use for end users. Since the USB Specification is released, Great progress has been achieved. Many USB Mass Storage products based on it have been developed, such as USB portable disk,USB CD-ROM,USB Flash disk and so on. Firstly, this dissertation introduces the importance of application of the USB mass storage device on smartphone and the background of USB. Secondly, we explain the protocols in different layers for developing USB mass storage device, including USB specification, BULK ONLY transport specification and SCSI commands for mass storage devices. At last, we focus on introducing the design method of firmware in USB Mass Storage Device based on USB general controllers. In this article, we tested the performance and practicability of Mass Storage Device. Furthermore, it concerns of the topic about extending usage of USB to the field of accelerating the development of embedded software. This application and test based on the USB1.1 Protocol and Bulk-Only Protocol. It is helpful for in-depth research, exploitation of Mass Storage Device.