说明：  原创：xmodem协议介绍及VxWorks下的应用 最初，XMODEM协议是一种基于调制解调器直接拨号通讯的文件传输协议，用来支持两台计算机之间的文件传输。由于其简单可靠、实现方便的特性，现在已经广泛应用于嵌入式设备中。实现xmodem只需要微处理器带有串口控制器就行了，一般的8位单片机也能进行文件传输。
(Original: xmodem agreement under VxWorks introduction and application of the first, XMODEM protocol is based on a direct dial-up modem communications, file transfer protocol, used to support two file transfer between computers. Because of its simple and reliable to achieve the characteristics of convenience, is now widely used in embedded devices. Xmodem achieve only on the microprocessor controller with a serial line, the general single-chip 8-bit file transfer can be carried out.)