利用FPGA模拟SPI总线，可以与其他器件通信，比如MCU-FPGA simulation using SPI bus, you can communicate with other devices, such as the MCU

1.异步通信软件模拟2.基于RS-232的串口通信3.基于RS-485的多机通信4. I2C总线协议的软件实现5. SPI总线在单片机系统中的实现6.-wire-1. Asynchronous communication software simulation 2. Based on the RS-232 serial communication 3. Based on the RS-485 Multi-machine communication 4. I2C bus protocol soft

nios ii 软核的ds1302（模拟spi接口）总线驱动函数及函数声明-nios ii soft ds1302（spi） bus driver functions and function declaration