关于STM32F1 的SPI 操作讲解已经很普遍了，这里分享一下STM32F1 系列 SPI3 使用DMA 发送和接收，关于SPI3 DMA发送和 接收大多数所都是在中断中 执行的，其实原理一样都需要死循环，等待数据发送完毕后在执行下一步操作。
// 初始化SPI3
void SPI3_Init(void)
{GPIO_InitTypeDef GPIO_InitStructure;SPI_InitTypeDef SPI_InitStructure;DMA_InitTypeDef DMA_InitStructure;RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA2, ENABLE);RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA|RCC_APB2Periph_GPIOB|RCC_APB2Periph_AFIO, ENABLE);GPIO_PinRemapConfig(GPIO_Remap_SWJ_JTAGDisable , ENABLE); //禁止JTAG功能（保留SWD下载口）RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI3, ENABLE);GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3 | GPIO_Pin_4 | GPIO_Pin_5;GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(GPIOB, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin =GPIO_Pin_15; //PA15 =1GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(GPIOA, &GPIO_InitStructure);PAout(15)=1; 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(SPI3, &SPI_InitStructure);//使能DMA发送DMA_DeInit(DMA2_Channel2); DMA_InitStructure.DMA_PeripheralBaseAddr = (u32)&SPI3->DR; DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST; DMA_InitStructure.DMA_BufferSize = 1024; DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable; DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte; DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte; DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;DMA_InitStructure.DMA_Priority = DMA_Priority_Medium; DMA_InitStructure.DMA_M2M = DMA_M2M_Disable; DMA_Init(DMA2_Channel2, &DMA_InitStructure); //使能DMA接收DMA_DeInit(DMA2_Channel1);DMA_InitStructure.DMA_PeripheralBaseAddr = (u32)&SPI3->DR;DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;DMA_InitStructure.DMA_Priority = DMA_Priority_Medium;DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;DMA_Init(DMA2_Channel1, &DMA_InitStructure);SPI_I2S_DMACmd(SPI3, SPI_I2S_DMAReq_Rx, ENABLE);SPI_I2S_DMACmd(SPI3,SPI_I2S_DMAReq_Tx,ENABLE);SPI_Cmd(SPI3, ENABLE);
}
// 速度设置
void SPI3_SetSpeed(u8 SpeedSet)
{SPI3->CR1&=0XFFC7; SPI3->CR1|=SpeedSet;SPI_Cmd(SPI3,ENABLE);
}
// CPU发送
uint8_t SPI3_ReadWriteByte(u8 TxData)
{ while((SPI3->SR&1<<1)==0){; }SPI3->DR=TxData; while((SPI3->SR&1<<0)==0){; } while(SPI3->SR&(1<<7)){;}return SPI3->DR;
}
// SPI3 DMA发送
void DMA_SPI3_TX(uint8_t *buffer,uint16_t len)
{DMA2->IFCR |=(0xf<<4);DMA2_Channel2->CNDTR=len; //设置要传输的数据长度DMA2_Channel2->CMAR=(u32)buffer; //设置RAM缓冲区地址DMA2_Channel2->CCR|=0x1;while(!(DMA2->ISR&(1<<5))){;}while (SPI_I2S_GetFlagStatus(SPI3, SPI_I2S_FLAG_TXE) == RESET){;}DMA2_Channel2->CCR &=(uint32_t)~0x1;
}
// SPI3 DMA 接收
void DMA_SPI3_RX(uint8_t *buffer,uint16_t len)
{SPI3->CR1|=SPI_Direction_2Lines_RxOnly;buffer[0] = SPI3->DR;// 读取一次数据DMA2->IFCR |=(0xf<<0);DMA2_Channel1->CNDTR=len; //设置要传输的数据长度DMA2_Channel1->CMAR=(u32)buffer; //设置RAM缓冲区地址DMA2_Channel1->CCR|=0x1;while(!(DMA2->ISR&(1<<1))){;}DMA2_Channel1->CCR &=(uint32_t)~0x1;SPI3->CR1&=~SPI_Direction_2Lines_RxOnly;
}