FPGA时序逻辑设计：串行外围设备接口SPI从设备系统，包括串行时钟线SCK，主机输入/从机输出MISO，主机输出/从机输入MOSI和低电平有效的从机选择线SS。环境为Quartus。-FPGA Timing Logic Design: Serial Peripheral Interface SPI Slave Device System Includes Serial Clock Line SCK, Host Input/Slave Output MISO, Host Output/Slave