FM1702SL射频模块底层驱动源程序。-FM1702SL RF modules underlying driver source code.

51单片机控制FM1702的底层汇编程序代码，已测试通过-51 MCU control FM1702 underlying assembler code, have been tested

FM1702SL射频芯片对外接口为SPI总线方式，对FM1702的操作实际上就是通过SPI总线 对FM1702SL内部的相关寄存器进行读写操作，从而实现射频读/写卡功能。本驱动程序基于 FM2306A编写(兼容PIC指令集的其他MCU也同样试用)，通过IO口软件模拟SPI总线时序。-The external interface of the RF chip FM1702SL SPI bus way the FM1702 operation is actually through