Question
DMA Circular mode misalignment
Hi everyone!
I'm trying to figure out what's wrong with my SPI Peripheral continous transmitting/receiving via DMA in Circular Mode. I think I have coded a pretty basic "Hello, World" for working with DMA, I've just generated code from .ioc file and then added a simple logic. This is my main.c:
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file : main.c
* @brief : Main program body
******************************************************************************
* @attention
*
* Copyright (c) 2025 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 "main.h"
#include "dma.h"
#include "spi.h"
#include "usart.h"
#include "usb_otg.h"
#include "gpio.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
/* USER CODE END PTD */
/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
#define SPI3_BUFFER_SIZE 2
/* USER CODE END PD */
/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */
/* USER CODE END PM */
/* Private variables ---------------------------------------------------------*/
/* USER CODE BEGIN PV */
volatile uint8_t spi3_tx_buffer[SPI3_BUFFER_SIZE] = {0};
volatile uint8_t spi3_rx_buffer[SPI3_BUFFER_SIZE] = {0};
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
/* USER CODE BEGIN PFP */
void SPI3_Start_Comm(void);
/* USER CODE END PFP */
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
/* USER CODE END 0 */
/**
* @brief The application entry point.
* @retval int
*/
int main(void)
{
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
/* MCU Configuration--------------------------------------------------------*/
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
/* USER CODE BEGIN Init */
/* USER CODE END Init */
/* Configure the system clock */
SystemClock_Config();
/* USER CODE BEGIN SysInit */
/* USER CODE END SysInit */
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_DMA_Init();
MX_USART3_UART_Init();
MX_USB_OTG_FS_PCD_Init();
MX_SPI3_Init();
/* USER CODE BEGIN 2 */
SPI3_Start_Comm();
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
}
/* USER CODE END 3 */
}
/**
* @brief System Clock Configuration
* @retval None
*/
void SystemClock_Config(void)
{
RCC_OscInitTypeDef RCC_OscInitStruct = {0};
RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
/** Configure LSE Drive Capability
*/
HAL_PWR_EnableBkUpAccess();
/** Configure the main internal regulator output voltage
*/
__HAL_RCC_PWR_CLK_ENABLE();
__HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);
/** Initializes the RCC Oscillators according to the specified parameters
* in the RCC_OscInitTypeDef structure.
*/
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
RCC_OscInitStruct.HSEState = RCC_HSE_BYPASS;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
RCC_OscInitStruct.PLL.PLLM = 4;
RCC_OscInitStruct.PLL.PLLN = 216;
RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
RCC_OscInitStruct.PLL.PLLQ = 9;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
{
Error_Handler();
}
/** Activate the Over-Drive mode
*/
if (HAL_PWREx_EnableOverDrive() != HAL_OK)
{
Error_Handler();
}
/** Initializes the CPU, AHB and APB buses clocks
*/
RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
|RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV4;
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_7) != HAL_OK)
{
Error_Handler();
}
}
/* USER CODE BEGIN 4 */
/**
* @brief This function starts SPI Communication for Peripheral device
* @retval None
*/
void SPI3_Start_Comm(void)
{
HAL_SPI_TransmitReceive_DMA(&hspi3,(uint8_t*)spi3_tx_buffer,
(uint8_t*)spi3_rx_buffer,SPI3_BUFFER_SIZE);
}
void HAL_SPI_TxRxCpltCallback(SPI_HandleTypeDef *hspi)
{
if(hspi->Instance == SPI3)
{
spi3_tx_buffer[0] = spi3_rx_buffer[0];
spi3_tx_buffer[1] = spi3_rx_buffer[1];
}
}
/* USER CODE END 4 */
/**
* @brief This function is executed in case of error occurrence.
* @retval None
*/
void Error_Handler(void)
{
/* USER CODE BEGIN Error_Handler_Debug */
/* User can add his own implementation to report the HAL error return state */
__disable_irq();
while (1)
{
}
/* USER CODE END Error_Handler_Debug */
}
#ifdef USE_FULL_ASSERT
/**
* @brief Reports the name of the source file and the source line number
* where the assert_param error has occurred.
* file: pointer to the source file name
* line: assert_param error line source number
* @retval None
*/
void assert_failed(uint8_t *file, uint32_t line)
{
/* USER CODE BEGIN 6 */
/* User can add his own implementation to report the file name and line number,
ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
/* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */
As you can see, I just start communication in SPI3_Start_Comm() and then in HAL_SPI_TxRxCpltCallback I prepare the bytes received at N-time to echo back at N+1-time.
What I get is the peripheral echoing back bytes at N+x-time, after three or four garbage results at first. If I print results from controller point of view this is what I get:
COPI CIPO
0: 0000 XXXX (garbage)
1: 0000 XXXX (garbage)
2: 0800 XXXX (garbage)
3: 0800 XXXX (garbage)
4: 1000 0000 (N+3 echo back - it should be N+1 or 0800). Missing N = 0 echo
5: 1000 0800 (and so on...)
6: 1800 0800
7: 1800 1000
8: 2000 1000
9: 2000 1800
10: 2800 1800
11: 2800 2000
12: 3000 2000
13: 3000 2800
14: 3800 2800
15: 3800 3000
16: 0000 3000
17: 0000 3800
18: 0800 3800
19: 0800 0000
20: 1000 0000
...
Peripheral device is STM32F722ZE. Controller is a black box.
Here's my spi.c and dma.c files generated from .ioc:
spi.c:
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file spi.c
* @brief This file provides code for the configuration
* of the SPI instances.
******************************************************************************
* @attention
*
* Copyright (c) 2025 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 "spi.h"
/* USER CODE BEGIN 0 */
/* USER CODE END 0 */
SPI_HandleTypeDef hspi3;
DMA_HandleTypeDef hdma_spi3_rx;
DMA_HandleTypeDef hdma_spi3_tx;
/* SPI3 init function */
void MX_SPI3_Init(void)
{
/* USER CODE BEGIN SPI3_Init 0 */
/* USER CODE END SPI3_Init 0 */
/* USER CODE BEGIN SPI3_Init 1 */
/* USER CODE END SPI3_Init 1 */
hspi3.Instance = SPI3;
hspi3.Init.Mode = SPI_MODE_SLAVE;
hspi3.Init.Direction = SPI_DIRECTION_2LINES;
hspi3.Init.DataSize = SPI_DATASIZE_8BIT;
hspi3.Init.CLKPolarity = SPI_POLARITY_HIGH;
hspi3.Init.CLKPhase = SPI_PHASE_2EDGE;
hspi3.Init.NSS = SPI_NSS_HARD_INPUT;
hspi3.Init.FirstBit = SPI_FIRSTBIT_MSB;
hspi3.Init.TIMode = SPI_TIMODE_DISABLE;
hspi3.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
hspi3.Init.CRCPolynomial = 7;
hspi3.Init.CRCLength = SPI_CRC_LENGTH_DATASIZE;
hspi3.Init.NSSPMode = SPI_NSS_PULSE_DISABLE;
if (HAL_SPI_Init(&hspi3) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN SPI3_Init 2 */
/* USER CODE END SPI3_Init 2 */
}
void HAL_SPI_MspInit(SPI_HandleTypeDef* spiHandle)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
if(spiHandle->Instance==SPI3)
{
/* USER CODE BEGIN SPI3_MspInit 0 */
/* USER CODE END SPI3_MspInit 0 */
/* SPI3 clock enable */
__HAL_RCC_SPI3_CLK_ENABLE();
__HAL_RCC_GPIOA_CLK_ENABLE();
__HAL_RCC_GPIOB_CLK_ENABLE();
/**SPI3 GPIO Configuration
PA4 ------> SPI3_NSS
PB3 ------> SPI3_SCK
PB4 ------> SPI3_MISO
PB5 ------> SPI3_MOSI
*/
GPIO_InitStruct.Pin = GPIO_PIN_4;
GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
GPIO_InitStruct.Alternate = GPIO_AF6_SPI3;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
GPIO_InitStruct.Pin = GPIO_PIN_3|GPIO_PIN_4|GPIO_PIN_5;
GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
GPIO_InitStruct.Alternate = GPIO_AF6_SPI3;
HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
/* SPI3 DMA Init */
/* SPI3_RX Init */
hdma_spi3_rx.Instance = DMA1_Stream0;
hdma_spi3_rx.Init.Channel = DMA_CHANNEL_0;
hdma_spi3_rx.Init.Direction = DMA_PERIPH_TO_MEMORY;
hdma_spi3_rx.Init.PeriphInc = DMA_PINC_DISABLE;
hdma_spi3_rx.Init.MemInc = DMA_MINC_ENABLE;
hdma_spi3_rx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
hdma_spi3_rx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
hdma_spi3_rx.Init.Mode = DMA_CIRCULAR;
hdma_spi3_rx.Init.Priority = DMA_PRIORITY_VERY_HIGH;
hdma_spi3_rx.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
if (HAL_DMA_Init(&hdma_spi3_rx) != HAL_OK)
{
Error_Handler();
}
__HAL_LINKDMA(spiHandle,hdmarx,hdma_spi3_rx);
/* SPI3_TX Init */
hdma_spi3_tx.Instance = DMA1_Stream5;
hdma_spi3_tx.Init.Channel = DMA_CHANNEL_0;
hdma_spi3_tx.Init.Direction = DMA_MEMORY_TO_PERIPH;
hdma_spi3_tx.Init.PeriphInc = DMA_PINC_DISABLE;
hdma_spi3_tx.Init.MemInc = DMA_MINC_ENABLE;
hdma_spi3_tx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
hdma_spi3_tx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
hdma_spi3_tx.Init.Mode = DMA_CIRCULAR;
hdma_spi3_tx.Init.Priority = DMA_PRIORITY_VERY_HIGH;
hdma_spi3_tx.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
if (HAL_DMA_Init(&hdma_spi3_tx) != HAL_OK)
{
Error_Handler();
}
__HAL_LINKDMA(spiHandle,hdmatx,hdma_spi3_tx);
/* SPI3 interrupt Init */
HAL_NVIC_SetPriority(SPI3_IRQn, 0, 0);
HAL_NVIC_EnableIRQ(SPI3_IRQn);
/* USER CODE BEGIN SPI3_MspInit 1 */
/* USER CODE END SPI3_MspInit 1 */
}
}
void HAL_SPI_MspDeInit(SPI_HandleTypeDef* spiHandle)
{
if(spiHandle->Instance==SPI3)
{
/* USER CODE BEGIN SPI3_MspDeInit 0 */
/* USER CODE END SPI3_MspDeInit 0 */
/* Peripheral clock disable */
__HAL_RCC_SPI3_CLK_DISABLE();
/**SPI3 GPIO Configuration
PA4 ------> SPI3_NSS
PB3 ------> SPI3_SCK
PB4 ------> SPI3_MISO
PB5 ------> SPI3_MOSI
*/
HAL_GPIO_DeInit(GPIOA, GPIO_PIN_4);
HAL_GPIO_DeInit(GPIOB, GPIO_PIN_3|GPIO_PIN_4|GPIO_PIN_5);
/* SPI3 DMA DeInit */
HAL_DMA_DeInit(spiHandle->hdmarx);
HAL_DMA_DeInit(spiHandle->hdmatx);
/* SPI3 interrupt Deinit */
HAL_NVIC_DisableIRQ(SPI3_IRQn);
/* USER CODE BEGIN SPI3_MspDeInit 1 */
/* USER CODE END SPI3_MspDeInit 1 */
}
}
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
dma.c:
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file dma.c
* @brief This file provides code for the configuration
* of all the requested memory to memory DMA transfers.
******************************************************************************
* @attention
*
* Copyright (c) 2025 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 "dma.h"
/* USER CODE BEGIN 0 */
/* USER CODE END 0 */
/*----------------------------------------------------------------------------*/
/* Configure DMA */
/*----------------------------------------------------------------------------*/
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
/**
* Enable DMA controller clock
*/
void MX_DMA_Init(void)
{
/* DMA controller clock enable */
__HAL_RCC_DMA1_CLK_ENABLE();
/* DMA interrupt init */
/* DMA1_Stream0_IRQn interrupt configuration */
HAL_NVIC_SetPriority(DMA1_Stream0_IRQn, 0, 0);
HAL_NVIC_EnableIRQ(DMA1_Stream0_IRQn);
/* DMA1_Stream1_IRQn interrupt configuration */
HAL_NVIC_SetPriority(DMA1_Stream1_IRQn, 0, 0);
HAL_NVIC_EnableIRQ(DMA1_Stream1_IRQn);
/* DMA1_Stream3_IRQn interrupt configuration */
HAL_NVIC_SetPriority(DMA1_Stream3_IRQn, 0, 0);
HAL_NVIC_EnableIRQ(DMA1_Stream3_IRQn);
/* DMA1_Stream5_IRQn interrupt configuration */
HAL_NVIC_SetPriority(DMA1_Stream5_IRQn, 0, 0);
HAL_NVIC_EnableIRQ(DMA1_Stream5_IRQn);
}
/* USER CODE BEGIN 2 */
/* USER CODE END 2 */
What am I missing?
Thanks to anyone who will try to help!