说明：  SPI接口的实现以及对外设的读写操作，其中包扩了几种工作方式，同时可以读取外设的版本号，传输速率可以达到2Mbps
(SPI interface implementation, as well as read and write operations on the peripheral, which extended several work packages at the same time can read the version number of peripherals, transfer rate up to 2Mbps)