void SPI2_Init(void)
{
SPI_InitTypeDef SPI_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
////SPI Set PB13,14,15 as Output push-pull - SCK, MISO and MOSI
RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI2,ENABLE);
/* 使能SPI引脚相关的时钟 */
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOB,ENABLE);
/*指令IO的复用功能*/
GPIO_PinAFConfig(GPIOB, GPIO_PinSource13,GPIO_AF_SPI2);
GPIO_PinAFConfig(GPIOB, GPIO_PinSource14,GPIO_AF_SPI2);
GPIO_PinAFConfig(GPIOB, GPIO_PinSource15,GPIO_AF_SPI2);
/* SCK、MOSI、MISO */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13|GPIO_Pin_14|GPIO_Pin_15;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF; //复用
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; //推挽
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_40MHz;
GPIO_Init(GPIOB,&GPIO_InitStructure);
/* SPI2 configuration */
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_High;
SPI_InitStructure.SPI_CPHA = SPI_CPHA_2Edge;
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(SPI2, &SPI_InitStructure);
/* Enable SPI2 */
SPI_Cmd(SPI2, ENABLE);
SPI2_ReadWriteByte(0xff);
}
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//SPIx 读写一个字节
//TxData:要写入的字节
//返回值:读取到的字节
uint8_t SPI2_ReadWriteByte(uint8_t TxData)
{
uint8_t retry=0;
while (SPI_I2S_GetFlagStatus(SPI2, SPI_I2S_FLAG_TXE) == RESET) //检查指定的SPI标志位设置与否:发送缓存空标志位
{
retry++;
if(retry>200)return 0;
}
SPI_I2S_SendData(SPI2, TxData); //通过外设SPIx发送一个数据
retry=0;
while (SPI_I2S_GetFlagStatus(SPI2, SPI_I2S_FLAG_RXNE) == RESET) //检查指定的SPI标志位设置与否:接受缓存非空标志位
{
retry++;
if(retry>200)return 0;
}
return SPI_I2S_ReceiveData(SPI2); //返回通过SPIx最近接收的数据
}
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//读取芯片ID
//返回值如下:
//0XEF13,表示芯片型号为W25Q80
//0XEF14,表示芯片型号为W25Q16
//0XEF15,表示芯片型号为W25Q32
//0XEF16,表示芯片型号为W25Q64
//0XEF17,表示芯片型号为W25Q128
uint16_t W25QXX_ReadID(void)
{
uint16_t Temp = 0;
GPIO_ResetBits(GPIOB,GPIO_Pin_12);
SPI2_ReadWriteByte(0x90);//发送读取ID命令
SPI2_ReadWriteByte(0x00);
SPI2_ReadWriteByte(0x00);
SPI2_ReadWriteByte(0x00);
Temp|=SPI2_ReadWriteByte(0x00)<<8;
Temp|=SPI2_ReadWriteByte(0x00);
GPIO_SetBits(GPIOB,GPIO_Pin_12);
return Temp;
}
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