| The Universal Serial Bus (USB) is specified to be an industry standard extension to the PC architecture. For the advantages of low cost, easy to use, protocol flexible, interface standardization and port easy to expand, USB (Universal Serial Bus) occupies the predominant position in the region of computer peripheral interface. It has become increasingly widespread in application. This topic designed USB Universal control interface based on the USB theory, making use of EPP parallel interface function of CH341 interface chips and USB current control interface is designed to carry out reading and writing control for the outside equipments. To verify its function, I prepared the source code of the functions that a PC transmission dynamic data to switch, and the test proved that the design of USB interface is success. This design comprises the requirements of the capacity of the designers in many facets, has strong theoretical research significance and practical value.In this paper, a simple analysis of the Universal Serial Bus USB (Universal Serial Bus) the generation, development, and USB device research situation at home and abroad. Then the paper introduced the USB bus protocol, including the USB bus architecture, USB physical layer, USB devices, USB Host, USB data stream and so on. On this basis, the paper designed the USB interface hardware, detailed USB controller chip CH341 characteristics, EPP parallel port function and application method. Then I discussed the complete process use of program-controlled switching system CH341 chip design USB interface and elaborated on concrete methods. Through researched the USB interface, designed hardware and debugged software, hoping to gain experience in this regard and facilitate the future development of USB peripherals. This article describes the following USB-based program-controlled switching system. After repeated debugging, the computer successfully passed the USB interface the paper designed and enables peripheral control functions. Finally, the paper described the USB technology, prospects and outlook. The section contains two aspects----the USB OTG protocol and its applications, and wireless USB technology. After which these two aspects can also conduct in-depth study and discussion. Future, these two aspects can also conduct in-depth study and discussion.The design scheme and theoretical analysis form a base for further research, and provide reference for other USB control systems. |
