Question
stm32N6 usart Configuration DMA Cyclic Receiving
When I was using STM32N6, I tried to generate USART with STM32CubeMx, but when you enable DCache the DMA did not properly handle USART-RX data.
The USART startup code is as follows
static FIXED_DMA_USER_RAM uint8_t s_ulDebugUsartRxDmaFifo[16];
bool DevUsartInit(void) {
bool ret = false;
//HAL_UART_DeInit(&huart1);
//MX_USART1_UART_Init();
memset(s_ulDebugUsartRxDmaFifo, 0, sizeof(s_ulDebugUsartRxDmaFifo));
if (HAL_UARTEx_ReceiveToIdle_DMA(&huart1, s_ulDebugUsartRxDmaFifo, sizeof(s_ulDebugUsartRxDmaFifo)) == HAL_OK) {
ret = true;
}
__DSB();
return ret;
}
/**
* @brief The application entry point.
* @retval int
*/
int main(void)
{
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
/* MPU Configuration--------------------------------------------------------*/
MPU_Config();
/* Enable the CPU Cache */
/* Enable I-Cache---------------------------------------------------------*/
SCB_EnableICache();
/* Enable D-Cache---------------------------------------------------------*/
SCB_EnableDCache();
/* MCU Configuration--------------------------------------------------------*/
HAL_Init();
/* USER CODE BEGIN Init */
/* USER CODE END Init */
/* USER CODE BEGIN SysInit */
/* USER CODE END SysInit */
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_GPDMA1_Init();
MX_USART1_UART_Init();
MX_TIM2_Init();
SystemIsolation_Config();
/* USER CODE BEGIN 2 */
DevUsartInit();
/* USER CODE END 2 */
/* Init scheduler */
osKernelInitialize();
/* Call init function for freertos objects (in app_freertos.c) */
MX_FREERTOS_Init();
/* Start scheduler */
osKernelStart();
/* We should never get here as control is now taken by the scheduler */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
}
/* USER CODE END 3 */
}
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file usart.c
* @brief This file provides code for the configuration
* of the USART instances.
******************************************************************************
* @attention
*
* Copyright (c) 2026 STMicroelectronics.
* All rights reserved.
*
* This software is licensed under terms that can be found in the LICENSE file
* in the root directory of this software component.
* If no LICENSE file comes with this software, it is provided AS-IS.
*
******************************************************************************
*/
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "usart.h"
/* USER CODE BEGIN 0 */
/* USER CODE END 0 */
UART_HandleTypeDef huart1;
DMA_HandleTypeDef handle_GPDMA1_Channel1;
DMA_NodeTypeDef Node_GPDMA1_Channel0;
DMA_QListTypeDef List_GPDMA1_Channel0;
DMA_HandleTypeDef handle_GPDMA1_Channel0;
/* USART1 init function */
void MX_USART1_UART_Init(void)
{
/* USER CODE BEGIN USART1_Init 0 */
/* USER CODE END USART1_Init 0 */
/* USER CODE BEGIN USART1_Init 1 */
/* USER CODE END USART1_Init 1 */
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();
}
/* USER CODE BEGIN USART1_Init 2 */
/* USER CODE END USART1_Init 2 */
}
void HAL_UART_MspInit(UART_HandleTypeDef* uartHandle)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
DMA_NodeConfTypeDef NodeConfig= {0};
RCC_PeriphCLKInitTypeDef PeriphClkInitStruct = {0};
if(uartHandle->Instance==USART1)
{
/* USER CODE BEGIN USART1_MspInit 0 */
/* USER CODE END USART1_MspInit 0 */
/** Initializes the peripherals clock
*/
PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_USART1;
PeriphClkInitStruct.Usart1ClockSelection = RCC_USART1CLKSOURCE_CLKP;
if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct) != HAL_OK)
{
Error_Handler();
}
/* USART1 clock enable */
__HAL_RCC_USART1_CLK_ENABLE();
__HAL_RCC_GPIOE_CLK_ENABLE();
/**USART1 GPIO Configuration
PE5 ------> USART1_TX
PE6 ------> USART1_RX
*/
GPIO_InitStruct.Pin = GPIO_PIN_5;
GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
GPIO_InitStruct.Alternate = GPIO_AF7_USART1;
HAL_GPIO_Init(GPIOE, &GPIO_InitStruct);
GPIO_InitStruct.Pin = GPIO_PIN_6;
GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
GPIO_InitStruct.Pull = GPIO_PULLUP;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
GPIO_InitStruct.Alternate = GPIO_AF7_USART1;
HAL_GPIO_Init(GPIOE, &GPIO_InitStruct);
/* USART1 DMA Init */
/* GPDMA1_REQUEST_USART1_TX Init */
handle_GPDMA1_Channel1.Instance = GPDMA1_Channel1;
handle_GPDMA1_Channel1.Init.Request = GPDMA1_REQUEST_USART1_TX;
handle_GPDMA1_Channel1.Init.BlkHWRequest = DMA_BREQ_SINGLE_BURST;
handle_GPDMA1_Channel1.Init.Direction = DMA_PERIPH_TO_MEMORY;
handle_GPDMA1_Channel1.Init.SrcInc = DMA_SINC_INCREMENTED;
handle_GPDMA1_Channel1.Init.DestInc = DMA_DINC_FIXED;
handle_GPDMA1_Channel1.Init.SrcDataWidth = DMA_SRC_DATAWIDTH_BYTE;
handle_GPDMA1_Channel1.Init.DestDataWidth = DMA_DEST_DATAWIDTH_BYTE;
handle_GPDMA1_Channel1.Init.Priority = DMA_LOW_PRIORITY_LOW_WEIGHT;
handle_GPDMA1_Channel1.Init.SrcBurstLength = 1;
handle_GPDMA1_Channel1.Init.DestBurstLength = 1;
handle_GPDMA1_Channel1.Init.TransferAllocatedPort = DMA_SRC_ALLOCATED_PORT0|DMA_DEST_ALLOCATED_PORT0;
handle_GPDMA1_Channel1.Init.TransferEventMode = DMA_TCEM_BLOCK_TRANSFER;
handle_GPDMA1_Channel1.Init.Mode = DMA_NORMAL;
if (HAL_DMA_Init(&handle_GPDMA1_Channel1) != HAL_OK)
{
Error_Handler();
}
__HAL_LINKDMA(uartHandle, hdmatx, handle_GPDMA1_Channel1);
/* GPDMA1_REQUEST_USART1_RX Init */
NodeConfig.NodeType = DMA_GPDMA_LINEAR_NODE;
NodeConfig.Init.Request = GPDMA1_REQUEST_USART1_RX;
NodeConfig.Init.BlkHWRequest = DMA_BREQ_SINGLE_BURST;
NodeConfig.Init.Direction = DMA_PERIPH_TO_MEMORY;
NodeConfig.Init.SrcInc = DMA_SINC_FIXED;
NodeConfig.Init.DestInc = DMA_DINC_INCREMENTED;
NodeConfig.Init.SrcDataWidth = DMA_SRC_DATAWIDTH_BYTE;
NodeConfig.Init.DestDataWidth = DMA_DEST_DATAWIDTH_BYTE;
NodeConfig.Init.SrcBurstLength = 1;
NodeConfig.Init.DestBurstLength = 1;
NodeConfig.Init.TransferAllocatedPort = DMA_SRC_ALLOCATED_PORT0|DMA_DEST_ALLOCATED_PORT0;
NodeConfig.Init.TransferEventMode = DMA_TCEM_BLOCK_TRANSFER;
NodeConfig.Init.Mode = DMA_NORMAL;
NodeConfig.TriggerConfig.TriggerPolarity = DMA_TRIG_POLARITY_MASKED;
NodeConfig.TriggerConfig.TriggerSelection = GPDMA1_TRIGGER_GPDMA1_CH0_TCF;
NodeConfig.DataHandlingConfig.DataExchange = DMA_EXCHANGE_NONE;
NodeConfig.DataHandlingConfig.DataAlignment = DMA_DATA_RIGHTALIGN_ZEROPADDED;
NodeConfig.SrcSecure = DMA_CHANNEL_SRC_SEC;
NodeConfig.DestSecure = DMA_CHANNEL_DEST_SEC;
if (HAL_DMAEx_List_BuildNode(&NodeConfig, &Node_GPDMA1_Channel0) != HAL_OK)
{
Error_Handler();
}
if (HAL_DMAEx_List_InsertNode(&List_GPDMA1_Channel0, NULL, &Node_GPDMA1_Channel0) != HAL_OK)
{
Error_Handler();
}
if (HAL_DMAEx_List_SetCircularMode(&List_GPDMA1_Channel0) != HAL_OK)
{
Error_Handler();
}
handle_GPDMA1_Channel0.Instance = GPDMA1_Channel0;
handle_GPDMA1_Channel0.InitLinkedList.Priority = DMA_LOW_PRIORITY_LOW_WEIGHT;
handle_GPDMA1_Channel0.InitLinkedList.LinkStepMode = DMA_LSM_FULL_EXECUTION;
handle_GPDMA1_Channel0.InitLinkedList.LinkAllocatedPort = DMA_LINK_ALLOCATED_PORT0;
handle_GPDMA1_Channel0.InitLinkedList.TransferEventMode = DMA_TCEM_BLOCK_TRANSFER;
handle_GPDMA1_Channel0.InitLinkedList.LinkedListMode = DMA_LINKEDLIST_CIRCULAR;
if (HAL_DMAEx_List_Init(&handle_GPDMA1_Channel0) != HAL_OK)
{
Error_Handler();
}
if (HAL_DMAEx_List_LinkQ(&handle_GPDMA1_Channel0, &List_GPDMA1_Channel0) != HAL_OK)
{
Error_Handler();
}
__HAL_LINKDMA(uartHandle, hdmarx, handle_GPDMA1_Channel0);
/* USART1 interrupt Init */
HAL_NVIC_SetPriority(USART1_IRQn, 5, 0);
HAL_NVIC_EnableIRQ(USART1_IRQn);
/* USER CODE BEGIN USART1_MspInit 1 */
/* USER CODE END USART1_MspInit 1 */
}
}
void HAL_UART_MspDeInit(UART_HandleTypeDef* uartHandle)
{
if(uartHandle->Instance==USART1)
{
/* USER CODE BEGIN USART1_MspDeInit 0 */
/* USER CODE END USART1_MspDeInit 0 */
/* Peripheral clock disable */
__HAL_RCC_USART1_CLK_DISABLE();
/**USART1 GPIO Configuration
PE5 ------> USART1_TX
PE6 ------> USART1_RX
*/
HAL_GPIO_DeInit(GPIOE, GPIO_PIN_5|GPIO_PIN_6);
/* USART1 DMA DeInit */
HAL_DMA_DeInit(uartHandle->hdmatx);
HAL_DMA_DeInit(uartHandle->hdmarx);
/* USART1 interrupt Deinit */
HAL_NVIC_DisableIRQ(USART1_IRQn);
/* USER CODE BEGIN USART1_MspDeInit 1 */
/* USER CODE END USART1_MspDeInit 1 */
}
}
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
