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 =1
- GPIO_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;
- }
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