单片机模拟SPI程序

1、(CPHA)(CPOL)的不同组合使得SPI 4 如果CPOL = 引脚在空闲状态保持低电平；如果CPOL 引脚在空闲状态保持高电平时序图如下：（一） AVR 单片机实现代码/IO 端口定义#define SPI_SCKPC0 #define SPI_MOSI PC1 #define SPI_MISO PC2 #define SPI_DDRDDRC #define SPI_PORT #define SPI_PINPINC/端口操作符定义#define SCK_SET SPI_PORT|=_BV(SPI_SCK) #define SCK_CLR SPI_PORT&=_BV(SPI-SCK)#de

2、fine MOSI_SET SPI_PORT|=_BV(SPI_MOSI)#define MOSI_CLR SPI_PORT&=_BV(SPI_MOSI)#define MISO_PIN PINC&_BV(SPI_MISO)#define DELAY_BUS/如需要延时，用延时函数替代此符号/模式 1：CPOL=1 CPHA=1void spi_init(void)SCK_SET; SPI_DDR|=_BV(SPI_MOSI)|_BV(SPI_SCK);uint8_t spi_readwrite_byte(uint8_t data)uint8_t i,ret=0;for(i=0;i8;i+)/

3、下降沿模拟if(data&0 x80)/设置输出MOSI_SET;elseMOSI_CLR;SCK_CRL;/SCK DELAY_BUS;/ 上 升 沿 模 拟 ret=1; if(MISO_PIN)/读数据ret|=1;SCK_SET; /SCK 产生上升沿data=1;DELAY_BUS;return ret;/模式 2：CPOL=0 CPHA=1void spi_init(void)SCK_CLR; SPI_DDR|=_BV(SPI_MOSI)|_BV(SPI_SCK);uint8_t spi_readwrite_byte(uint8_t data)uint8_t i,ret=0;for

4、(i=0;i8;i+)/上升沿模拟if(data&0 x80)/设置输出MOSI_SET;elseMOSI_CLR;SCK_SET;/SCK DELAY_BUS;/ 下 降 沿 模 拟 ret=1; if(MISO_PIN)/读数据ret|=1;SCK_CLR; /SCK 产生下降沿data=1;DELAY_BUS;return ret;/模式 3：CPOL=1 CPHA=0void spi_init(void)SCK_SET; SPI_DDR|=_BV(SPI_MOSI)|_BV(SPI_SCK);uint8_t spi_readwrite_byte(uint8_t data)uint8_t

5、 i,ret=0;/设置好输出口if(data&0 x80)MOSI_SET;elseMOSI_CLR;for(i=0;i8;i+)DELAY_BUS;/ 下 降 沿 模 拟 ret=1; if(MISO_PIN)/读数据ret|=1;SCK_CRL;/SCK 产生下降沿DELAY_BUS;/上升沿模拟data=1;if(data&0 x80)/设置输出MOSI_SET;elseMOSI_CLR;SCK_SET; /SCK 产生上升沿return ret;/模式 4：CPOL=0 CPHA=0void spi_init(void)SCK_CLR; SPI_DDR|=_BV(SPI_MOSI)|

6、_BV(SPI_SCK);uint8_t spi_readwrite_byte(uint8_t data)uint8_t i,ret=0;/设置好输出口if(data&0 x80)MOSI_SET;elseMOSI_CLR;for(i=0;i8;i+)DELAY_BUS;/上升沿模拟ret=1;if(MISO_PIN)/读数据ret|=1;SCK_SET;/SCK 产生上升沿DELAY_BUS;/下降沿模拟data=1;if(data&0 x80)/设置输出MOSI_SET;elseMOSI_CLR;SCK_CLR; /SCK 产生下降沿return ret;（二） 其它单片机实现代码#inc

7、lude #define _CPOL1#define _CPHA0#define SCK_IODDRA|=0X01 #define MOSI_IODDRA|=0X02 #define MISO_IO#define SSEL_IODDRA|=0X08#define SCK_D(X) (X?(PORTA|=0X01):(PORTA&=0XFE) #define MOSI_D(X) (X?(PORTA|=0X02):(PORTA&=0XFD) #define SSEL_D(X) (X?(PORTA|=0X08):(PORTA&=0XF7)#define MISO_I()void delay()uns

8、igned char m,n; for(n=0;n5;n+); for(m=0;m100;m+);/*端口方向配置 与输出初始化*/ void SPI_Init(void)SCK_IO; MOSI_IOMISO_IO; SSEL_IO; SSEL_D(1); MOSI_D(1); #if _CPOL=0 SCK_D(0);#else SCK_D(1);#endif/*模式零写数据*/ #if _CPOL=0&_CPHA=0/MODE0void SPI_Send_Dat(unsigned char dat)unsigned char n; for(n=0;n8;n+)SCK_D(0);if(da

9、t&0 x80)MOSI_D(1); else MOSI_D(0); dat=1;SCK_D(1);SCK_D(0);/*模式零读数据*/ unsigned char SPI_Receiver_Dat(void)unsigned char n ,dat,bit_t; for(n=0;n8;n+)SCK_D(0);dat=1; if(MISO_I()dat|=0 x01; else dat&=0 xfe; SCK_D(1);SCK_D(0);return dat;#endif/*模式二写数据*/ #if _CPOL=1&_CPHA=0/MODE1void SPI_Send_Dat(unsigne

10、d char dat)unsigned char n; for(n=0;n8;n+)SCK_D(1);if(dat&0 x80)MOSI_D(1); else MOSI_D(0); dat=1;SCK_D(0);SCK_D(1);/*模式二读数据*/ unsigned char SPI_Receiver_Dat(void)unsigned char n ,dat,bit_t; for(n=0;n8;n+)SCK_D(1);dat=1; if(MISO_I()dat|=0 x01; else dat&=0 xfe; SCK_D(0);SCK_D(1);return dat;#endif/*模式一

11、写数据*/#if _CPOL=0&_CPHA=1/MODE01void SPI_Send_Dat(unsigned char dat)unsigned char n;SCK_D(0);for(n=0;n8;n+)SCK_D(1);if(dat&0 x80)MOSI_D(1); else MOSI_D(0); dat=1;SCK_D(0);/*模式一读数据*/ unsigned char SPI_Receiver_Dat(void)unsigned char n ,dat,bit_t; for(n=0;n8;n+)SCK_D(1);dat=1; if(MISO_I()dat|=0 x01; el

12、se dat&=0 xfe; SCK_D(0);SCK_D(0);return dat;#endif/#if _CPOL=1&_CPHA=1/MODE11void SPI_Send_Dat(unsigned char dat)unsigned char n;SCK_D(1);for(n=0;n8;n+)SCK_D(0);if(dat&0 x80)MOSI_D(1); else MOSI_D(0); dat=1;SCK_D(1);/*模式三读数据*/ unsigned char SPI_Receiver_Dat(void)unsigned char n ,dat,bit_t; SCK_D(0);for(n=0;n8;n+) SCK_D(0);dat=1; if(MISO_I()dat|=0 x01; else dat&=0 xfe; SCK_D(1);SCK_D(1);return dat;#endif/*/ void main()SPI