在使用STM32的HAL库进行SPI DMA传输时,默认情况下,DMA传输的数据量是受限于DMA传输计数器的位宽。对于STM32的DMA控制器,通常传输计数器的位宽是16位,因此单次DMA传输的最大数据量为2^16(即65536字节)。
如果你希望实现更大的数据传输(例如2^32字节),可以考虑以下几种方法:
1. 分段传输
你可以将大数据传输分成多个小段,每段的数据量不超过2^16字节。在每次DMA传输完成后,通过DMA传输完成中断或回调函数来启动下一段传输。这种方法不需要修改硬件或库,但需要在软件中进行额外的处理。
#define MAX_DMA_TRANSFER_SIZE 65536
void SPI_Transmit_DMA_Large(SPI_HandleTypeDef *hspi, uint8_t *pData, uint32_t Size)
{
uint32_t remainingSize = Size;
uint8_t *pCurrentData = pData;
while (remainingSize > 0)
{
uint16_t transferSize = (remainingSize > MAX_DMA_TRANSFER_SIZE) ? MAX_DMA_TRANSFER_SIZE : remainingSize;
HAL_SPI_Transmit_DMA(hspi, pCurrentData, transferSize);
pCurrentData += transferSize;
remainingSize -= transferSize;
// 等待当前传输完成
while (HAL_SPI_GetState(hspi) != HAL_SPI_STATE_READY);
}
}
2. 使用双缓冲模式
某些STM32系列支持DMA的双缓冲模式。你可以配置两个DMA缓冲区,当一个缓冲区正在传输时,另一个缓冲区可以准备下一批数据。通过这种方式,可以实现连续的大数据传输。
3. 使用硬件特性
某些STM32系列(如STM32F4、STM32F7、STM32H7等)的DMA控制器支持更大的传输计数器位宽(例如32位)。如果你的STM32芯片支持更大的DMA传输计数器,你可以直接配置DMA传输计数器的位宽为32位。
例如,在STM32H7系列中,DMA传输计数器可以配置为32位。你可以通过修改DMA初始化代码来设置更大的传输计数器:
hdma_spi_tx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
hdma_spi_tx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
hdma_spi_tx.Init.Mode = DMA_NORMAL;
hdma_spi_tx.Init.Priority = DMA_PRIORITY_HIGH;
hdma_spi_tx.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
hdma_spi_tx.Init.FIFOThreshold = DMA_FIFO_THRESHOLD_FULL;
hdma_spi_tx.Init.MemBurst = DMA_MBURST_SINGLE;
hdma_spi_tx.Init.PeriphBurst = DMA_PBURST_SINGLE;
hdma_spi_tx.Init.Direction = DMA_MEMORY_TO_PERIPH;
hdma_spi_tx.Init.PeriphInc = DMA_PINC_DISABLE;
hdma_spi_tx.Init.MemInc = DMA_MINC_ENABLE;
hdma_spi_tx.Init.DataAlignment = DMA_PDATAALIGN_BYTE;
hdma_spi_tx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
hdma_spi_tx.Init.Mode = DMA_NORMAL;
hdma_spi_tx.Init.Priority = DMA_PRIORITY_HIGH;
hdma_spi_tx.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
hdma_spi_tx.Init.FIFOThreshold = DMA_FIFO_THRESHOLD_FULL;
hdma_spi_tx.Init.MemBurst = DMA_MBURST_SINGLE;
hdma_spi_tx.Init.PeriphBurst = DMA_PBURST_SINGLE;
hdma_spi_tx.Init.Direction = DMA_MEMORY_TO_PERIPH;
hdma_spi_tx.Init.PeriphInc = DMA_PINC_DISABLE;
hdma_spi_tx.Init.MemInc = DMA_MINC_ENABLE;
hdma_spi_tx.Init.DataAlignment = DMA_PDATAALIGN_BYTE;
hdma_spi_tx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
hdma_spi_tx.Init.Mode = DMA_NORMAL;
hdma_spi_tx.Init.Priority = DMA_PRIORITY_HIGH;
hdma_spi_tx.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
hdma_spi_tx.Init.FIFOThreshold = DMA_FIFO_THRESHOLD_FULL;
hdma_spi_tx.Init.MemBurst = DMA_MBURST_SINGLE;
hdma_spi_tx.Init.PeriphBurst = DMA_PBURST_SINGLE;
hdma_spi_tx.Init.Direction = DMA_MEMORY_TO_PERIPH;
hdma_spi_tx.Init.PeriphInc = DMA_PINC_DISABLE;
hdma_spi_tx.Init.MemInc = DMA_MINC_ENABLE;
hdma_spi_tx.Init.DataAlignment = DMA_PDATAALIGN_BYTE;
hdma_spi_tx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
hdma_spi_tx.Init.Mode = DMA_NORMAL;
hdma_spi_tx.Init.Priority = DMA_PRIORITY_HIGH;
hdma_spi_tx.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
hdma_spi_tx.Init.FIFOThreshold = DMA_FIFO_THRESHOLD_FULL;
hdma_spi_tx.Init.MemBurst = DMA_MBURST_SINGLE;
hdma_spi_tx.Init.PeriphBurst = DMA_PBURST_SINGLE;
hdma_spi_tx.Init.Direction = DMA_MEMORY_TO_PERIPH;
hdma_spi_tx.Init.PeriphInc = DMA_PINC_DISABLE;
hdma_spi_tx.Init.MemInc = DMA_MINC_ENABLE;
hdma_spi_tx.Init.DataAlignment = DMA_PDATAALIGN_BYTE;
hdma_spi_tx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
hdma_spi_tx.Init.Mode = DMA_NORMAL;
hdma_spi_tx.Init.Priority = DMA_PRIORITY_HIGH;
hdma_spi_tx.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
hdma_spi_tx.Init.FIFOThreshold = DMA_FIFO_THRESHOLD_FULL;
hdma_spi_tx.Init.MemBurst = DMA_MBURST_SINGLE;
hdma_spi_tx.Init.PeriphBurst = DMA_PBURST_SINGLE;
hdma_spi_tx.Init.Direction = DMA_MEMORY_TO_PERIPH;
hdma_spi_tx.Init.PeriphInc = DMA_PINC_DISABLE;
hdma_spi_tx.Init.MemInc = DMA_MINC_ENABLE;
hdma_spi_tx.Init.DataAlignment = DMA_PDATAALIGN_BYTE;
hdma_spi_tx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
hdma_spi_tx.Init.Mode = DMA_NORMAL;
hdma_spi_tx.Init.Priority = DMA_PRIORITY_HIGH;
hdma_spi_tx.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
hdma_spi_tx.Init.FIFOThreshold = DMA_FIFO_THRESHOLD_FULL;
hdma_spi_tx.Init.MemBurst = DMA_MBURST_SINGLE;
hdma_spi_tx.Init.PeriphBurst = DMA_PBURST_SINGLE;
hdma_spi_tx.Init.Direction = DMA_MEMORY_TO_PERIPH;
hdma_spi_tx.Init.PeriphInc = DMA_PINC_DISABLE;
hdma_spi_tx.Init.MemInc = DMA_MINC_ENABLE;
hdma_spi_tx.Init.DataAlignment = DMA_PDATAALIGN_BYTE;
hdma_spi_tx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
hdma_spi_tx.Init.Mode = DMA_NORMAL;
hdma_spi_tx.Init.Priority = DMA_PRIORITY_HIGH;
hdma_spi_tx.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
hdma_spi_tx.Init.FIFOThreshold = DMA_FIFO_THRESHOLD_FULL;
hdma_spi_tx.Init.MemBurst = DMA_MBURST_SINGLE;
hdma_spi_tx.Init.PeriphBurst = DMA_PBURST_SINGLE;
hdma_spi_tx.Init.Direction = DMA_MEMORY_TO_PERIPH;
hdma_spi_tx.Init.PeriphInc = DMA_PINC_DISABLE;
hdma_spi_tx.Init.MemInc = DMA_MINC_ENABLE;
hdma_spi_tx.Init.DataAlignment = DMA_PDATAALIGN_BYTE;
hdma_spi_tx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
hdma_spi_tx.Init.Mode = DMA_NORMAL;
hdma_spi_tx.Init.Priority = DMA_PRIORITY_HIGH;
hdma_spi_tx.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
hdma_spi_tx.Init.FIFOThreshold = DMA_FIFO_THRESHOLD_FULL;
hdma_spi_tx.Init.MemBurst = DMA_MBURST_SINGLE;
hdma_spi_tx.Init.PeriphBurst = DMA_PBURST_SINGLE;
hdma_spi_tx.Init.Direction = DMA_MEMORY_TO_PERIPH;
hdma_spi_tx.Init.PeriphInc = DMA_PINC_DISABLE;
hdma_spi_tx.Init.MemInc = DMA_MINC_ENABLE;
hdma_spi_tx.Init.DataAlignment = DMA_PDATAALIGN_BYTE;
hdma_spi_tx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
hdma_spi_tx.Init.Mode = DMA_NORMAL;
hdma_spi_tx.Init.Priority = DMA_PRIORITY_HIGH;
hdma_spi_tx.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
hdma_spi_tx.Init.FIFOThreshold = DMA_FIFO_THRESHOLD_FULL;
hdma_spi_tx.Init.MemBurst = DMA_MBURST_SINGLE;
hdma_spi_tx.Init.PeriphBurst = DMA_PBURST_SINGLE;
hdma_spi_tx.Init.Direction = DMA_MEMORY_TO_PERIPH;
hdma_spi_tx.Init.PeriphInc = DMA_PINC_DISABLE;
hdma_spi_tx.Init.MemInc = DMA_MINC_ENABLE;
hdma_spi_tx.Init.DataAlignment = DMA_PDATAALIGN_BYTE;
hdma_spi_tx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
hdma_spi_tx.Init.Mode = DMA_NORMAL;
hdma_spi_tx.Init.Priority = DMA_PRIORITY_HIGH;
hdma_spi_tx.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
hdma_spi_tx.Init.FIFOThreshold = DMA_FIFO_THRESHOLD_FULL;
hdma_spi_tx.Init.MemBurst = DMA_MBURST_SINGLE;
hdma_spi_tx.Init.PeriphBurst = DMA_PBURST_SINGLE;
hdma_spi_tx.Init.Direction = DMA_MEMORY_TO_PERIPH;
hdma_spi_tx.Init.PeriphInc = DMA_PINC_DISABLE;
hdma_spi_tx.Init.MemInc = DMA_MINC_ENABLE;
hdma_spi_tx.Init.DataAlignment = DMA_PDATAALIGN_BYTE;
hdma_spi_tx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
hdma_spi_tx.Init.Mode = DMA_NORMAL;
hdma_spi_tx.Init.Priority = DMA_PRIORITY_HIGH;
hdma_spi_tx.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
hdma_spi_tx.Init.FIFOThreshold = DMA_FIFO_THRESHOLD_FULL;
hdma_spi_tx.Init.MemBurst = DMA_MBURST_SINGLE;
hdma_spi_tx.Init.PeriphBurst = DMA_PBURST_SINGLE;
hdma_spi_tx.Init.Direction = DMA_MEMORY_TO_PERIPH;
hdma_spi_tx.Init.PeriphInc = DMA_PINC_DISABLE;
hdma_spi_tx.Init.MemInc = DMA_MINC_ENABLE;
hdma_spi_tx.Init.DataAlignment = DMA_PDATAALIGN_BYTE;
hdma_spi_tx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
hdma_spi_tx.Init.Mode = DMA_NORMAL;
hdma_spi_tx.Init.Priority = DMA_PRIORITY_HIGH;
hdma_spi_tx.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
hdma_spi_tx.Init.FIFOThreshold = DMA_FIFO_THRESHOLD_FULL;
hdma_spi_tx.Init.MemBurst = DMA_MBURST_SINGLE;
hdma_spi_tx.Init.PeriphBurst = DMA_PBURST_SINGLE;
hdma_spi_tx.Init.Direction = DMA_MEMORY_TO_PERIPH;
hdma_spi_tx.Init.PeriphInc = DMA_PINC_DISABLE;
hdma_spi_tx.Init.MemInc = DMA_MINC_ENABLE;
hdma_spi_tx.Init.DataAlignment = DMA_PDATAALIGN_BYTE;
hdma_spi_tx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
hdma_spi_tx.Init.Mode = DMA_NORMAL;
hdma_spi_tx.Init.Priority = DMA_PRIORITY_HIGH;
hdma_spi_tx.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
hdma_spi_tx.Init.FIFOThreshold = DMA_FIFO_THRESHOLD_FULL;
hdma_spi_tx.Init.MemBurst = DMA_MBURST_SINGLE;
hdma_spi_tx.Init.PeriphBurst = DMA_PBURST_SINGLE;
hdma_spi_tx.Init.Direction = DMA_MEMORY_TO_PERIPH;
hdma_spi_tx.Init.PeriphInc = DMA_PINC_DISABLE;
hdma_spi_tx.Init.MemInc = DMA_MINC_ENABLE;
hdma_spi_tx.Init.DataAlignment = DMA_PDATAALIGN_BYTE;
hdma_spi_tx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
hdma_spi_tx.Init.Mode = DMA_NORMAL;
hdma_spi_tx.Init.Priority = DMA_PRIORITY_HIGH;
hdma_spi_tx.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
hdma_spi_tx.Init.FIFOThreshold = DMA_FIFO_THRESHOLD_FULL;
hdma_spi_tx.Init.MemBurst = DMA_MBURST_SINGLE;
hdma_spi_tx.Init.PeriphBurst = DMA_PBURST_SINGLE;
hdma_spi_tx.Init.Direction = DMA_MEMORY_TO_PERIPH;
hdma_spi_tx.Init.PeriphInc = DMA_PINC_DISABLE;
hdma_spi_tx.Init.MemInc = DMA_MINC_ENABLE;
hdma_spi_tx.Init.DataAlignment = DMA_PDATAALIGN_BYTE;
hdma_spi_tx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
hdma_spi_tx.Init.Mode = DMA_NORMAL;
hdma_spi_tx.Init.Priority = DMA_PRIORITY_HIGH;
hdma_spi_tx.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
hdma_spi_tx.Init.FIFOThreshold = DMA_FIFO_THRESHOLD_FULL;
hdma_spi_tx.Init.MemBurst = DMA_MBURST_SINGLE;
hdma_spi