c - 如何使用 DMA 将源阵列复制到目标阵列(使用 CMSIS CORE)？

Question

我在 stm32f103rc 中尝试 DMA。我按照这个教程https://letanphuc.net/2014/06/how-to-use-stm32-dma/并使用 CMSIS CORE 编写了我自己的代码。在这里，我采用两个数组，其中一个是“sourceArr”，其中存储一个随机值，并在 DMA 的帮助下将该数组复制到“destArr”。

DMA 相关函数定义和变量

volatile uint32_t status = 0;
uint32_t sourceArr[ARRAYSIZE];
uint32_t destArr[ARRAYSIZE];

#define DMA1_CLOCK_EN()     (RCC->AHBENR = RCC_AHBENR_DMA1EN) 
#define DMA1_CHANNEL1_EN()  (DMA1_Channel1->CCR |= DMA_CCR1_EN)     //((uint16_t)0x0001)

void DMA1_Channel1_IRQHandler(void)
{
    if (DMA1->ISR & DMA_ISR_TCIF1)
    {
        status = 1;
        Blink_Led(5000);
        DMA1->IFCR |= DMA_IFCR_CTCIF1;
    }
}

void NVIC_Init()
{
     NVIC_EnableIRQ(DMA1_Channel1_IRQn);
     NVIC_SetPriority(DMA1_Channel1_IRQn, 0);
}

void DMA_Init(void)
{
    DMA1_Channel1->CCR |= DMA_CCR1_MEM2MEM;     /*Memory to memory transfer enable  ((uint16_t)0x4000)*/
    DMA1_Channel1->CCR &= ~DMA_CCR1_CIRC;               /* circular mode* ((uint16_t)0x0020) */
    /* Priroty set as medium PL[1:0] = 01 */
    DMA1_Channel1->CCR |= DMA_CCR1_PL_0;   //((uint16_t)0x1000)
    /* source and destination data size set as 32bit */
    DMA1_Channel1->CCR |= DMA_CCR1_MSIZE_1;  //((uint16_t)0x0800)
    DMA1_Channel1->CCR |= DMA_CCR1_PSIZE_1;  //((uint16_t)0x0200) 
    /* Auto increment of memory enabled for source and destination */
    DMA1_Channel1->CCR |= DMA_CCR1_PINC;     //((uint16_t)0x0040)
    DMA1_Channel1->CCR |= DMA_CCR1_MINC;     //((uint16_t)0x0080)
    /* Data transfer direction set as read from peripheral*/
    DMA1_Channel1->CCR &= ~DMA_CCR1_DIR;     //((uint16_t)0x0010)
    /* source and destination start addresses */
    DMA1_Channel1->CPAR = (uint32_t)&sourceArr;
    DMA1_Channel1->CMAR = (uint32_t)&destArr;
    /* Enable DMA1 Channel Transfer Complete interrupt */
  DMA1_Channel1->CCR |= DMA_CCR1_TCIE;     //((uint16_t)0x0002)

}

void DMA_DeInit(void)
{
    DMA1_Channel1->CCR &= (uint16_t)~DMA_CCR1_EN;   /* Disable the selected DMAy Channelx */
    DMA1_Channel1->CCR = 0;                                             /* Reset DMAy Channelx control register */
    DMA1_Channel1->CNDTR = 0;                                           /* Reset DMAy Channelx remaining bytes register */
    DMA1_Channel1->CPAR = 0;                                            /* Reset DMAy Channelx peripheral address register */
    DMA1_Channel1->CMAR = 0;                                            /* Reset DMAy Channelx memory address register */
    DMA1->IFCR  |= DMA_IFCR_CGIF1 | DMA_IFCR_CTCIF1 | DMA_IFCR_CHTIF1 | DMA_IFCR_CTEIF1;        /* Reset interrupt pending bits for DMA1 Channel1 */

}

主要

int main(void)
{
    int i;
    for (i=0;i<ARRAYSIZE;i++)
        sourceArr[i] = i;
    Led_Init();
    Blink_Led(1000);
    DMA1_CLOCK_EN();        //enable clock for DMA
    DMA_DeInit();
    DMA_Init();
    NVIC_Init();
    Blink_Led(1000);
    status = 0;
    __enable_irq();
    DMA1_CHANNEL1_EN();  //Enable DMA1 Channel 1 transfer
    while(status==0);
    Blink_Led(1000);
    for (i=0; i<ARRAYSIZE;i++)
  {
     destArr[i]=sourceArr[i];
  }
    Blink_Led(1000);

    while (1)
    {

    }
}

如果一切正常，则会闪烁 5 次。主函数中有 4 个，IRQ 中有 1 个。

但我只眨眼两次。

任何建议都会非常有帮助。

提前致谢

Answer 1

您应该设置要传输的数据数量

DMA1_Channel1->CNDTR = ARRAYSIZE;

在使用 DMA1_CHANNEL1_EN() 启用 channel 之前。