On an L412KB Nucleo, I configured TIM1 to use ETR2 as a clock source and set the counter period to 1 so that every time a rising edge occurs on the TIM1_ETR pin occurs, it should trigger a DMA. I set up DMA1/Ch6 to respond to TIM_UP for a byte sized peripheral-to-memory from GPIOA (since my D0-D7 input parallel data is on those pins).
I can start the TIM1 and verify it is triggering if I enable its interrupt. That works. However, I do not see the DMA happening when I examine the destination memory, nor is a DMA interrupt generated (it is also enabled in NVIC). So I can't tell where the failure is coming from. (I expect to see `byteBuffer` fill with &GPIOA->IDR which is hardwired externally to 0x82, but it remains zero). Did I forget to turn something on / enable something?
Here's the `main.c`:
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file : main.c
* @brief : Main program body
******************************************************************************
* @attention
*
* <h2><center>© Copyright (c) 2022 STMicroelectronics.
* All rights reserved.</center></h2>
*
* This software component is licensed by ST under BSD 3-Clause license,
* the "License"; You may not use this file except in compliance with the
* License. You may obtain a copy of the License at:
* opensource.org/licenses/BSD-3-Clause
*
******************************************************************************
*/
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.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 */
/* USER CODE END PD */
/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */
/* USER CODE END PM */
/* Private variables ---------------------------------------------------------*/
I2C_HandleTypeDef hi2c1;
TIM_HandleTypeDef htim1;
TIM_HandleTypeDef htim2;
DMA_HandleTypeDef hdma_tim1_up;
/* USER CODE BEGIN PV */
volatile uint8_t idr = 0;
volatile uint8_t byteBuff[256];
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_I2C1_Init(void);
static void MX_TIM2_Init(void);
static void MX_DMA_Init(void);
static void MX_TIM1_Init(void);
/* USER CODE BEGIN PFP */
/* 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();
SystemClock_Config();
MX_GPIO_Init();
MX_I2C1_Init();
MX_TIM2_Init();
MX_DMA_Init();
MX_TIM1_Init();
idr = GPIOA->IDR;
HAL_DMA_Start_IT(&hdma_tim1_up, (uint32_t)&(GPIOA->IDR), (uint32_t)byteBuff, 0x10);
HAL_RCC_MCOConfig(RCC_MCO1, RCC_MCO1SOURCE_MSI, RCC_MCODIV_2);
HAL_TIM_Base_Start(&htim1);
while (1)
{
}
}
static void MX_TIM1_Init(void)
{
TIM_ClockConfigTypeDef sClockSourceConfig = {0};
TIM_MasterConfigTypeDef sMasterConfig = {0};
htim1.Instance = TIM1;
htim1.Init.Prescaler = 0;
htim1.Init.CounterMode = TIM_COUNTERMODE_UP;
htim1.Init.Period = 1;
htim1.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
htim1.Init.RepetitionCounter = 0;
htim1.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_ENABLE;
if (HAL_TIM_Base_Init(&htim1) != HAL_OK)
{
Error_Handler();
}
sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_ETRMODE2;
sClockSourceConfig.ClockPolarity = TIM_CLOCKPOLARITY_NONINVERTED;
sClockSourceConfig.ClockPrescaler = TIM_CLOCKPRESCALER_DIV1;
sClockSourceConfig.ClockFilter = 15;
if (HAL_TIM_ConfigClockSource(&htim1, &sClockSourceConfig) != HAL_OK)
{
Error_Handler();
}
sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
sMasterConfig.MasterOutputTrigger2 = TIM_TRGO2_RESET;
sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
if (HAL_TIMEx_MasterConfigSynchronization(&htim1, &sMasterConfig) != HAL_OK)
{
Error_Handler();
}
}
static void MX_DMA_Init(void)
{
__HAL_RCC_DMA1_CLK_ENABLE();
HAL_NVIC_SetPriority(DMA1_Channel6_IRQn, 0, 0);
HAL_NVIC_EnableIRQ(DMA1_Channel6_IRQn);
}
... and here's the MSP code ...
void HAL_TIM_Base_MspInit(TIM_HandleTypeDef* htim_base)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
if(htim_base->Instance==TIM1)
{
__HAL_RCC_TIM1_CLK_ENABLE();
__HAL_RCC_GPIOA_CLK_ENABLE();
/**TIM1 GPIO Configuration
PA12 ------> TIM1_ETR
*/
GPIO_InitStruct.Pin = GPIO_PIN_12;
GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
GPIO_InitStruct.Alternate = GPIO_AF1_TIM1;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
/* TIM1 DMA Init */
/* TIM1_UP Init */
hdma_tim1_up.Instance = DMA1_Channel6;
hdma_tim1_up.Init.Request = DMA_REQUEST_7;
hdma_tim1_up.Init.Direction = DMA_PERIPH_TO_MEMORY;
hdma_tim1_up.Init.PeriphInc = DMA_PINC_DISABLE;
hdma_tim1_up.Init.MemInc = DMA_MINC_ENABLE;
hdma_tim1_up.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
hdma_tim1_up.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
hdma_tim1_up.Init.Mode = DMA_NORMAL;
hdma_tim1_up.Init.Priority = DMA_PRIORITY_HIGH;
if (HAL_DMA_Init(&hdma_tim1_up) != HAL_OK)
{
Error_Handler();
}
__HAL_LINKDMA(htim_base,hdma[TIM_DMA_ID_UPDATE],hdma_tim1_up);
/* TIM1 interrupt Init */
HAL_NVIC_SetPriority(TIM1_BRK_TIM15_IRQn, 0, 0);
HAL_NVIC_EnableIRQ(TIM1_BRK_TIM15_IRQn);
HAL_NVIC_SetPriority(TIM1_UP_TIM16_IRQn, 0, 0);
HAL_NVIC_EnableIRQ(TIM1_UP_TIM16_IRQn);
HAL_NVIC_SetPriority(TIM1_TRG_COM_IRQn, 0, 0);
HAL_NVIC_EnableIRQ(TIM1_TRG_COM_IRQn);
HAL_NVIC_SetPriority(TIM1_CC_IRQn, 0, 0);
HAL_NVIC_EnableIRQ(TIM1_CC_IRQn);
/* USER CODE BEGIN TIM1_MspInit 1 */
:
:
