This is a study for device driver design and implementation of VxWorks - based embedded system. In the analysis of system level structure and the relationship between the driver calls, for the design of the device driver framework of the VxWorks~based embedded system, proposes the concept of virtual device driver layer, whose location is between I/O system and the real driver, The virtual device driver layer manages the real hardware drivers in every way, and also manages the communication between I/O systems and real drivers. The read/write ring buffer zone is given to solve the speed of synchronization of the low-speed devices and processors, which greatly reduces the overhead and improves driver performance. The development of device drivers in real time as well as reliability application requirements could been met through the use of the concept of the virtual device driver layer.%针对基于VxWorks嵌入式系统的设备驱动的设计与实现展开研究.在分析系统层次结构和设备驱动调用关系的基础上,对基于VxWorks嵌入式系统的设备驱动框架结构设计,提出了虚拟设备驱动层这一理念,虚拟设备驱动层处在I/O系统和真实驱动程序之间,通过虚拟设备驱动层来统一管理各真实硬件驱动,同时还管理着I/O系统和真实驱动程序之间的通信;通过给出的读写环形缓冲区解决了低速设备和处理器两者的速度同步问题,大大降低了系统开销,提高了驱动程序的性能；通过使用虚拟设备驱动层这一理念开发设备驱动在可靠性和实时性方面都能满足应用要求.
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