1. 程式人生 > >GD32除錯Si4438,SPI通訊終於調通

GD32除錯Si4438,SPI通訊終於調通

最近用GD32去除錯si4438,SPI讀取資料總是出錯,因為之前做過GD32移植STM32的SPI程式,初始化程式碼如下:訪問訪問W25Q16  FLASH晶片是沒有任何問題的,但是用在si4438上就是不行。
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1, ENABLE);       //使能SPI時鐘
	SPI_Cmd(SPI2, DISABLE);
	SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
	SPI_InitStructure.SPI_Mode = SPI_Mode_Master;
	SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;
//	SPI_InitStructure.SPI_CPOL = SPI_CPOL_Low;		         //STM32
//	SPI_InitStructure.SPI_CPHA = SPI_CPHA_1Edge;             //STM32
	SPI_InitStructure.SPI_CPOL = SPI_CPOL_High; 			 //GD
	SPI_InitStructure.SPI_CPHA = SPI_CPHA_2Edge;			 //GD
	SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;
	SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_2;
	SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
	SPI_InitStructure.SPI_CRCPolynomial = 7;
	SPI_Init(SPI1, &SPI_InitStructure);

	SPI_Cmd(SPI1, ENABLE);

最後我嘗試著修改各種配置,結果卻狠狠的扇了我一巴掌,原來上面就應該使用STM32的配置, 配置時鐘空閒時為Low電平,第1個時鐘沿捕獲資料;

正確配置如下:

	RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1, ENABLE);       //使能SPI時鐘
	SPI_Cmd(SPI2, DISABLE);
	SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
	SPI_InitStructure.SPI_Mode = SPI_Mode_Master;
	SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;
	SPI_InitStructure.SPI_CPOL = SPI_CPOL_Low;		         //STM32
	SPI_InitStructure.SPI_CPHA = SPI_CPHA_1Edge;             //STM32
//	SPI_InitStructure.SPI_CPOL = SPI_CPOL_High; 			 //GD
//	SPI_InitStructure.SPI_CPHA = SPI_CPHA_2Edge;			 //GD
	SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;
	SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_2;
	SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
	SPI_InitStructure.SPI_CRCPolynomial = 7;
	SPI_Init(SPI1, &SPI_InitStructure);

	SPI_Cmd(SPI1, ENABLE);

讀寫函式如下:

u8 SPI_SendByte(u8 byte)
{
	/* Loop while DR register in not emplty */
	while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_TXE) == RESET);
	
	/* Send byte through the SPI2 peripheral */
	SPI_I2S_SendData(SPI1, byte);
	
	/* Wait to receive a byte */
	while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_RXNE) == RESET);
	
	/* Return the byte read from the SPI bus */
	return SPI_I2S_ReceiveData(SPI1);
}

u8 SPI_ReadByte(void)
{
	return (SPI_SendByte(0x00));
}


最後總結:上電後SI4438的SDN腳應該拉低,並做一定延時才能正確讀取資料。