Solved
STM32U585 freezes on DMA transmission with USART peripheral
Hello,
I am implementing DMA transfers to USART1 peripheral configured as asynchronous UART. I am facing issue that the message transferred with DMA is transferred only once and freezes.
When set to transfer messages in blocking mode (without using DMA), it is transferred fine every time in a loop.
For reference I am attaching my initialization code for DMA and USART1:
Initialize USART1:
huart1.Instance = USART1;
huart1.Init.BaudRate = 115200;
huart1.Init.WordLength = UART_WORDLENGTH_8B;
huart1.Init.StopBits = UART_STOPBITS_1;
huart1.Init.Parity = UART_PARITY_NONE;
huart1.Init.Mode = UART_MODE_TX_RX;
huart1.Init.HwFlowCtl = UART_HWCONTROL_NONE;
huart1.Init.OverSampling = UART_OVERSAMPLING_16;
huart1.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE;
huart1.Init.ClockPrescaler = UART_PRESCALER_DIV1;
huart1.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
if (HAL_UART_Init(&huart1) != HAL_OK)
{
Error_Handler();
}
if (HAL_UARTEx_SetTxFifoThreshold(&huart1, UART_TXFIFO_THRESHOLD_1_8) != HAL_OK)
{
Error_Handler();
}
if (HAL_UARTEx_SetRxFifoThreshold(&huart1, UART_RXFIFO_THRESHOLD_1_8) != HAL_OK)
{
Error_Handler();
}
if (HAL_UARTEx_DisableFifoMode(&huart1) != HAL_OK)
{
Error_Handler();
}
Initialize DMA:
handle_GPDMA1_Channel0.Instance = GPDMA1_Channel0;
handle_GPDMA1_Channel0.Init.Request = GPDMA1_REQUEST_USART1_TX;
handle_GPDMA1_Channel0.Init.BlkHWRequest = DMA_BREQ_SINGLE_BURST;
handle_GPDMA1_Channel0.Init.Direction = DMA_MEMORY_TO_PERIPH;
handle_GPDMA1_Channel0.Init.SrcInc = DMA_SINC_INCREMENTED;
handle_GPDMA1_Channel0.Init.DestInc = DMA_DINC_FIXED;
handle_GPDMA1_Channel0.Init.SrcDataWidth = DMA_SRC_DATAWIDTH_BYTE;
handle_GPDMA1_Channel0.Init.DestDataWidth = DMA_DEST_DATAWIDTH_BYTE;
handle_GPDMA1_Channel0.Init.Priority = DMA_LOW_PRIORITY_LOW_WEIGHT;
handle_GPDMA1_Channel0.Init.SrcBurstLength = 1;
handle_GPDMA1_Channel0.Init.DestBurstLength = 1;
handle_GPDMA1_Channel0.Init.TransferAllocatedPort = DMA_SRC_ALLOCATED_PORT0|DMA_DEST_ALLOCATED_PORT0;
handle_GPDMA1_Channel0.Init.TransferEventMode = DMA_TCEM_BLOCK_TRANSFER;
handle_GPDMA1_Channel0.Init.Mode = DMA_NORMAL;
if (HAL_DMA_Init(&handle_GPDMA1_Channel0) != HAL_OK)
{
Error_Handler();
}
__HAL_LINKDMA(huart, hdmatx, handle_GPDMA1_Channel0);
if (HAL_DMA_ConfigChannelAttributes(&handle_GPDMA1_Channel0, DMA_CHANNEL_NPRIV) != HAL_OK)
{
Error_Handler();
}
and this is how I am sending UART messages:
while (1)
{
HAL_UART_Transmit_DMA(&huart1, (uint8_t*)"DMA Message\n", strlen("DMA Message"));
HAL_Delay(2000);
}
