The Design Of USB Driver Based On μC/OS-Ⅱ Operating System

USB (Universal Serial Bus) is a very important bus structure. Its lots of advantages, just as plug and play, hot plug and small volume of the interface have hugely changed the development of the technology of connecting computers to external equipments.μC/OS-Ⅱis an open-source, complete, portable, curable, well customizable real-time embedded operating system, which provides task management, time management, memory management, as well as communication and synchronization functions between the mission. It can be easily ported to a variety of microprocessors. SAMSUNG's S3C44B0X is the widely used SOC which is based on the ARM7TDMI core and it has a high-performance, low power consumption and low cost characteristics of embedded applications for many industries to provide cost-effective solutions.This issue uses S3C44B0X processor and the external interface components for designing embedded hardware test platform. On this hardware platform, we implement the USB communication control, keyboard management, LCD display, real-time operating systemμC/OS-Ⅱporting and other functions. According to standards of low cost, little consumption and fast speed, this paper has built a USB slave system with PDIUSBD12 chip as slave controlling chip. This system completes the enumeration, configuration and other functions of USB equipment, fulfills the design and application of USB core drive program and USB keyboard drive, and finally implements human interface device protocol on this system. As a major context for basic designing and developing of system software,μC/OS-Ⅱreal-time operating system is used for multi-task scheduling management. System program uses C language.In order to improve real-time and efficiency of system, part of the procedure cross-uses of C language and assembly language. After designing and testing, hardware and software have achieved what was set in the beginning. The test result indicated that USB drive program together with the system can be run successfully in context ofμC/OS-Ⅱoperating system and related running situation, then carries out USB keyboard testing and reading operation, hence, meeting the original design purpose of embedded USB slave system module.The completion of the subject provides a theoretical foundation and practice for achieving the USB data communication under non-PC machines. It has a wide range of practical application value.