2019年01月16日 | STM32F051 SPI slave mode DMA接收

用STM32F051的SPI从模式接收主机发送的实时数据。

Eclips 环境，gcc编译器，相关源码如下：

#ifdef DEBUG_SPI_EN

#define DEBUG_SPI(...)      printf(__VA_ARGS__)

#else

#define DEBUG_SPI(...)

#endif

void SPI1_Config(void)

{

    GPIO_InitTypeDef    GPIO_InitStructure;

    SPI_InitTypeDef     SPI_InitStructure;

    RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOB, ENABLE);

    // SPI1 port

    GPIO_InitStructure.GPIO_Pin   = GPIO_Pin_3 | GPIO_Pin_5;

    GPIO_InitStructure.GPIO_Mode  = GPIO_Mode_AF;

    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

    GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;

    GPIO_InitStructure.GPIO_PuPd  = GPIO_PuPd_UP;

    GPIO_Init(GPIOB, &GPIO_InitStructure);

    GPIO_PinAFConfig(GPIOB, GPIO_PinSource3, GPIO_AF_0);

    GPIO_PinAFConfig(GPIOB, GPIO_PinSource5, GPIO_AF_0);

    // SPI1 config

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1, ENABLE);

    SPI_I2S_DeInit(SPI1);

    SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_RxOnly;

    SPI_InitStructure.SPI_Mode      = SPI_Mode_Slave;  

    SPI_InitStructure.SPI_DataSize  = SPI_DataSize_8b; 

    SPI_InitStructure.SPI_CPOL      = SPI_CPOL_High;

    SPI_InitStructure.SPI_CPHA      = SPI_CPHA_1Edge;

    SPI_InitStructure.SPI_NSS       = SPI_NSS_Soft;    

    SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_4;  // SCLK = 12.0MHz

    SPI_InitStructure.SPI_FirstBit          = SPI_FirstBit_MSB;

    SPI_InitStructure.SPI_CRCPolynomial     = 7;

    SPI_Init(SPI1, &SPI_InitStructure);

    SPI_Cmd(SPI1, DISABLE);

}

void SPI1_DMA_NVIC_Config(void)

{

    NVIC_InitTypeDef    NVIC_InitStructure;

    NVIC_InitStructure.NVIC_IRQChannel         = DMA1_Channel2_3_IRQn;  

    NVIC_InitStructure.NVIC_IRQChannelPriority = 2; 

    NVIC_InitStructure.NVIC_IRQChannelCmd      = ENABLE;

    NVIC_Init(&NVIC_InitStructure);

    DMA_ITConfig(DMA1_Channel2, DMA_IT_TC, ENABLE);

}

void SPI1_DMA_Config(uint8_t *pbuff, uint16_t nbytes)

{

    DMA_InitTypeDef     DMA_InitStructure;

    RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);

    DMA_DeInit(DMA1_Channel2);

    DMA_StructInit(&DMA_InitStructure);

    DMA_Cmd(DMA1_Channel2, DISABLE);

    DMA_InitStructure.DMA_PeripheralBaseAddr= SPI1_BASE + 0x0C;

    DMA_InitStructure.DMA_MemoryBaseAddr    = (uint32_t)pbuff;

    DMA_InitStructure.DMA_BufferSize        = nbytes;

    DMA_InitStructure.DMA_DIR               = DMA_DIR_PeripheralSRC;        // from SPI

    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_High;

    DMA_InitStructure.DMA_M2M               = DMA_M2M_Disable;

    DMA_Init(DMA1_Channel2, &DMA_InitStructure);

    SPI1_DMA_NVIC_Config();

}

void SPI1_Read_Starting(uint8_t *pbuff, uint16_t nbytes)

{

    DMA_Cmd(DMA1_Channel2, DISABLE);

    DMA1_Channel2->CNDTR = nbytes;

    DMA1_Channel2->CPAR  = SPI1_BASE + 0x0C;

    DMA1_Channel2->CMAR  = (uint32_t)pbuff;

    DMA_Cmd(DMA1_Channel2, ENABLE);

    SPI_I2S_DMACmd(SPI1, SPI_I2S_DMAReq_Rx, ENABLE);

    SPI_Cmd(SPI1, ENABLE);

}

void SPI1_Read_Stop(void)

{

    SPI_I2S_DMACmd(SPI1, SPI_I2S_DMAReq_Rx, DISABLE);

    SPI_Cmd(SPI1, DISABLE);

}

/*

 *  SPI1_RX & SPI1_TX DMA Interrupt

 */

void DMA1_Channel2_3_IRQHandler(void)

{

    if(DMA_GetFlagStatus(DMA1_FLAG_TC2) != RESET)

    {

        DEBUG_SPI(">>");

        ; // 接收数据处理，略去...

        ;

        DMA_ClearITPendingBit(DMA1_FLAG_TC2);

    }

/*

    if(DMA_GetFlagStatus(DMA1_FLAG_TC3) != RESET)

    {

        DMA_ClearITPendingBit(DMA1_FLAG_TC3);

    }*/

}

/*

 *  片选中断设置

 */

void SPI1_NSS_Config(void)

{

    EXTI_InitTypeDef   EXTI_InitStructure;

    NVIC_InitTypeDef   NVIC_InitStructure;

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);

    SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOA, EXTI_PinSource15);

    EXTI_InitStructure.EXTI_Line    = EXTI_Line15;

    EXTI_InitStructure.EXTI_Mode    = EXTI_Mode_Interrupt;

    EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising_Falling;  // _Rising  _Falling  _Rising_Falling

    EXTI_InitStructure.EXTI_LineCmd = ENABLE;

    EXTI_Init(&EXTI_InitStructure);

    NVIC_InitStructure.NVIC_IRQChannel         = EXTI4_15_IRQn;

    NVIC_InitStructure.NVIC_IRQChannelPriority = 0; // Low Medium Hight VeryHigh: 0 - 3

    NVIC_InitStructure.NVIC_IRQChannelCmd      = ENABLE;

    NVIC_Init(&NVIC_InitStructure);

    EXTI_ClearITPendingBit(EXTI_Line15);

}

void EXTI4_15_IRQHandler(void)

{

    if(EXTI_GetITStatus(EXTI_Line15) != RESET)

    {

        EXTI_ClearITPendingBit(EXTI_Line15);

        GPIO_ReadInputDataBit(GPIOA, GPIO_Pin_15);

        if(GPIO_ReadInputDataBit(GPIOA, GPIO_Pin_15) == RESET)

        {

            SPI1_Read_Starting(&dmaBuffPoll[0], FRAME_BYTES);   // startup SPI1 Data receive-only

        }

    }

}

起初，SPI设成“1-line bidirectional data mode selected”模式，接收到的数据全为“0”，找了很久的原因，无果；

改为“Receive-only mode”后，一切正常！