TM4C1294 spi通讯

void init_spi(uint32_t ui32SysClock)
{
	SysCtlPeripheralEnable(SYSCTL_PERIPH_SSI2);//使能SPI2时钟

	SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOD);//使能GPIOD时钟

    GPIOPinConfigure(GPIO_PD0_SSI2XDAT1);//SPI2 IO 口定义
    GPIOPinConfigure(GPIO_PD1_SSI2XDAT0);
    GPIOPinConfigure(GPIO_PD2_SSI2FSS);
    GPIOPinConfigure(GPIO_PD3_SSI2CLK);

    GPIOPinTypeSSI(GPIO_PORTD_BASE, GPIO_PIN_0 | GPIO_PIN_1 | GPIO_PIN_2 |
                       GPIO_PIN_3);

#if defined(TARGET_IS_TM4C129_RA0) ||                                         \
    defined(TARGET_IS_TM4C129_RA1) ||                                         \
    defined(TARGET_IS_TM4C129_RA2)
    SSIConfigSetExpClk(SSI2_BASE, ui32SysClock, SSI_FRF_MOTO_MODE_0,
                       SSI_MODE_MASTER, 1000000, 8); //设置SSI 时钟 模式
#else
    SSIConfigSetExpClk(SSI2_BASE, SysCtlClockGet(), SSI_FRF_MOTO_MODE_0,
                       SSI_MODE_MASTER, 1000000, 8);
#endif

    SSIEnable(SSI2_BASE);//使能SPI2

	while(SSIDataGetNonBlocking(SSI2_BASE, &SpiReviceBuf[0])) //清除缓冲区
	{
	}


}

下面是一些操作函数

void Spi_WriteByte(uint8_t TxData)
{

	 while(SSIBusy(SSI2_BASE))
	 {
	 }
	SSIDataPut(SSI2_BASE,(uint32_t) TxData);
}

void Spi_Flash_Write_Enable(void)
{
	Spi_WriteByte(W25X_WriteEnable);
}



void Spi_Flash_Write_Disable(void)
{
	Spi_WriteByte(W25X_WriteDisable);
}


void W25QXX_Erase_Sector(uint32_t Dst_Addr)
{
	Dst_Addr*=4096;
	Spi_Flash_Write_Enable();
	W25QXX_Wait_Busy();

	Spi_WriteByte(W25X_SectorErase);
	Spi_WriteByte((uint8_t)((Dst_Addr)>>16));
	Spi_WriteByte((uint8_t)((Dst_Addr)>>8));
	Spi_WriteByte((uint8_t)((Dst_Addr)>>0));

	W25QXX_Wait_Busy();
}



uint8_t SPI_Flash_ReadSR(void)
{
	uint32_t data;
	Spi_WriteByte(W25X_ReadStatusReg);

	Spi_WriteByte(0xFF);
	while(SSIBusy(SSI2_BASE))
	{
	}
	SSIDataGet(SSI2_BASE,&data);
	return (uint8_t)data;
}

void W25QXX_Wait_Busy()
{
	uint8_t Status;


	do{
		Status = SPI_Flash_ReadSR();
		Status &= 0x01;
	}while(Status != 0);
}

void W25QXX_Read(uint8_t *pBuffer,uint32_t ReadAddr,uint16_t NumByteToRead)
{
	uint16_t i;
	uint32_t data;
	Spi_Flash_Write_Enable();
	Spi_WriteByte(W25X_ReadData);
	Spi_WriteByte((uint8_t)((ReadAddr)>>16));
	Spi_WriteByte((uint8_t)((ReadAddr)>>8));
	Spi_WriteByte((uint8_t)((ReadAddr)>>0));

	for(i=0;i<NumByteToRead;i++)
	{
	    Spi_WriteByte(0XFF);   //循环读数，只需要不停的发送0xff，就可以读出数据
	    while(SSIBusy(SSI2_BASE))
	    {
	    }
	  //  UARTprintf("%d  \n ",data);
	    SSIDataGet(SSI2_BASE,&data);
	    pBuffer[i] = (uint8_t)data;

	  //  UARTprintf("%x   ",pBuffer[i]);


	}

}

void W25QXX_Write_Page(uint8_t *pBuffer,uint32_t WriteAddr,uint16_t NumByteToWrite)
{
	uint16_t i;
	Spi_Flash_Write_Enable();
	Spi_WriteByte(W25X_PageProgram);

	Spi_WriteByte((uint8_t)((WriteAddr)>>16));
	Spi_WriteByte((uint8_t)((WriteAddr)>>8));
	Spi_WriteByte((uint8_t)((WriteAddr)>>0));

	for(i = 0;i < NumByteToWrite;i++)
	{
		Spi_WriteByte(pBuffer[i]);
	}
	W25QXX_Wait_Busy();
}

void W25QXX_Write_NoCheck(uint8_t *pBuffer,uint32_t WriteAddr,uint16_t NumByteToWrite)
{
	uint16_t pageremain;
	pageremain=256-WriteAddr%256;

	if(NumByteToWrite<=pageremain)
		pageremain=NumByteToWrite;

	while(1)
	{
		W25QXX_Write_Page(pBuffer,WriteAddr,pageremain);//要写入的字节数小或等于单页剩余的字节数直接写
		if(NumByteToWrite==pageremain)
			break;//写入结束了

		else //NumByteToWrite>pageremain，如果要写入的数据大于单页剩余的字节数。
		{
			pBuffer+=pageremain;
			WriteAddr+=pageremain;

			NumByteToWrite-=pageremain;  //减去已经写入了的字节数
			if(NumByteToWrite>256)
				pageremain=256; //一次可以写入256个字节
			else
				pageremain=NumByteToWrite;  //不够256个字节了
		}
	}
}

 mian函数中写入后读出的数据全为0

原理图