在学习VxWorks I/O 系统功能的基础上，了解的基本I/O、缓冲I/O 及格式化I/O、文件描述符、标准输入/输出/错误设备的使用。对VxWorks I/O 系统中常用的API 有较为深入的理解。实践者对I/O 系统的理解和使用的熟练程度将影响后续实践环节进行顺利与否。通过I/O 系统API 与应用程序交互，能方便地对所调试的系统进行监控，是实时嵌入环境软硬件开发的主要手段之一。实现终端显示的秒表。精确到1/10 秒。可键盘控制暂停/继续计时/复位功能。-In learning VxWorks I/O system functions on the basis of the understanding of the basic I/O, buffer I/O and formatted I/O, file descr iptor, standard input/output/error devices use. On the VxWorks I/O system is more commonly used API in depth understanding. Practice on the I/O system, the understanding and use of proficiency will have an impact on follow-up practice sessions were held smoothly or not. Through the I/O system API and interactive applications that can facilitate the debugging of system monitoring, real-time embedded environment development of hardware and software one of the main instruments. Realize terminal display stopwatch. Accurate to 1/10 seconds. Keyboard control can pause/resume timer/reset function.