spi2 slave模式的DMA接收问题

2019-07-20 03:47发布

STM32F767板子，这是我的spi2的dma 代码，配置为slave 接收模式，测试时发现，配置为8bit、16bit数据时，前面32bit的数据都接收不到，数据从接收buffer的第33bit位置开始填充，后续的接收数据正确。请问怎么回事？
请大神们指点。。。

#include "sys.h"
#include "misc.h"

SPI_HandleTypeDef SPI2_Handler;
DMA_HandleTypeDef DMA1_Handler;
#define LENGTH 128
uint8_t dma_rx[LENGTH] = {0xff};

void DMA1_Stream3_IRQHandler(void)
{
      int i = 0;
      if(       HAL_DMA_GetState(&DMA1_Handler) != RESET)
      {
            if(DMA1->LISR & (1 << 27))
            {
                     __HAL_DMA_DISABLE(&DMA1_Handler);
                     DMA1->LIFCR |= (1 << 27);
                     DMA1->LIFCR |= (1 << 26);
                     for(i = 0; i < LENGTH/2; i++)
                     {
                              printf("dma rx[%d] = %x ",i, dma_rx);
                     }
                     __HAL_DMA_ENABLE(&DMA1_Handler);
            }
      }
}

void myDMA_Init(void)
{
int i = 0;

      NVIC_InitTypeDef NVIC_InitStructure;
      SPI2_Handler.Instance = SPI2;
      SPI2_Handler.Init.Mode = SPI_MODE_SLAVE;
      SPI2_Handler.Init.Direction = SPI_DIRECTION_2LINES_RXONLY;
      SPI2_Handler.Init.DataSize = SPI_DATASIZE_8BIT;
      SPI2_Handler.Init.CLKPolarity = SPI_POLARITY_LOW;
      SPI2_Handler.Init.CLKPhase = SPI_PHASE_1EDGE;
      SPI2_Handler.Init.NSS = SPI_NSS_HARD_INPUT;
      SPI2_Handler.Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_16;             //256O?u
      SPI2_Handler.Init.FirstBit = SPI_FIRSTBIT_MSB;
      SPI2_Handler.Init.TIMode = SPI_TIMODE_DISABLE;
      SPI2_Handler.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
      SPI2_Handler.Init.CRCPolynomial = 7;
      HAL_SPI_Init(&SPI2_Handler);
      SPI2->CR2 |= 1 << 7;
      SPI2->CR2 |= 1 << 6;

      __HAL_RCC_DMA1_CLK_ENABLE();
      __HAL_LINKDMA(&SPI2_Handler, hdmarx, DMA1_Handler);
      DMA1_Handler.Instance = DMA1_Stream3;
      DMA1_Handler.Init.Channel = DMA_CHANNEL_0;
      DMA1_Handler.Init.Direction = DMA_PERIPH_TO_MEMORY;
      DMA1_Handler.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
      DMA1_Handler.Init.FIFOThreshold = DMA_FIFO_THRESHOLD_FULL;
      DMA1_Handler.Init.MemBurst = DMA_MBURST_SINGLE;
      DMA1_Handler.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
      DMA1_Handler.Init.MemInc = DMA_MINC_ENABLE;
      DMA1_Handler.Init.Mode = DMA_NORMAL;//DMA_CIRCULAR;//
      DMA1_Handler.Init.PeriphBurst = DMA_PBURST_SINGLE;
      DMA1_Handler.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
      DMA1_Handler.Init.PeriphInc = DMA_PINC_DISABLE;
      DMA1_Handler.Init.Priority = DMA_PRIORITY_VERY_HIGH;

      HAL_DMA_DeInit(&DMA1_Handler);
      HAL_DMA_Init(&DMA1_Handler);

      NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0);
      NVIC_InitStructure.NVIC_IRQChannel = DMA1_Stream3_IRQn;
      NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
      NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
      NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
      NVIC_Init(&NVIC_InitStructure);

      HAL_SPI_Receive_DMA(&SPI2_Handler, (uint8_t *)&dma_rx[0], LENGTH);
}

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