针对44b0芯片编写的一款Bootloader代码，使用Xmodem协议将代码下载到芯片中直接运行，对想要了解Bootloader和Xmodem协议的朋友很有帮助，笔者原创，已经经过测试运行。-Prepared for a chip 44b0 Bootloader code, use the Xmodem protocol to download the code to run directly on the chip, you want to understand the Bootloader

通过串口方式实现bootloader功能（非ISP）。可以直接下载hex文件将程序下载到指定Flash存储区。文件传输用Xmodem协议。 串口命令输入执行相关动作。 -The bootloader function (non-ISP) through the serial port. Hex file can be downloaded directly to the program is downloaded to the specified Flash memory area.

nxp的二级bootloader，基于xmode协议的。仿照官方例程做的，还是挺好用的。-nxp secondary bootloader, based xmodem protocol. Modeled official routine to do, or very good use.