说明：  共两个文件，一个是对网络芯片W5500进行控制的master spi接口，另一个是w5500命令控制逻辑，命令格式按照w5500芯片的要求，分为地址段，控制段和数据段进行统一控制。此外提供w5500芯片初始化及读写控制流程图。
(A total of two documents, one is the master SPI interface for network control chip W5500, the other is a w5500 command control logic, command format in accordance with the requirement of w5500 chip, divided into address segment, unified control and data segments. In addition to provide w5500 chip initialization and read and write control flow chart.)