该程序为 SPI 典型程序，主要是采用内部测试自循环模式，而且采用中断发送、接收形式，通过程序可以学习如何进行自循环测试以及如何编写 SPI 中断程序。-The typical procedure for the SPI program, mainly from the cyclic model with internal testing, and using interrupt sending, receiving the form, through the program can lear