MCU_STM32H7XX系列通过STM32CUBEMX配置MCO2

ゝ一纸荒年。 2023-01-10 01:22 156阅读 0赞

因为要给STM32H7xx系列的芯片配置MCO2输出，发现按网上的通过STM32CUBEMX配置死活不能启动MCO2，系统时钟配置如下

void SystemClock_Config(void)
    {
      RCC_OscInitTypeDef RCC_OscInitStruct = {0};
      RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
      RCC_PeriphCLKInitTypeDef PeriphClkInitStruct = {0};
    
      /** Supply configuration update enable 
      */ 
      HAL_PWREx_ConfigSupply(PWR_LDO_SUPPLY);
      /** Configure the main internal regulator output voltage 
      */
      __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE0);
    
      while(!__HAL_PWR_GET_FLAG(PWR_FLAG_VOSRDY)) {}
      /** Macro to configure the PLL clock source 
      */
      __HAL_RCC_PLL_PLLSOURCE_CONFIG(RCC_PLLSOURCE_HSE);
      /** Initializes the CPU, AHB and APB busses clocks 
      */
      RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
      RCC_OscInitStruct.HSEState = RCC_HSE_ON;
      RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
      RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
      RCC_OscInitStruct.PLL.PLLM = 1;
      RCC_OscInitStruct.PLL.PLLN = 80;
      RCC_OscInitStruct.PLL.PLLP = 2;
      RCC_OscInitStruct.PLL.PLLQ = 40;
      RCC_OscInitStruct.PLL.PLLR = 2;
      RCC_OscInitStruct.PLL.PLLRGE = RCC_PLL1VCIRANGE_3;
      RCC_OscInitStruct.PLL.PLLVCOSEL = RCC_PLL1VCOWIDE;
      RCC_OscInitStruct.PLL.PLLFRACN = 0;
      if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
      {
        Error_Handler();
      }
      /** Initializes the CPU, AHB and APB busses clocks 
      */
      RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                                  |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2
                                  |RCC_CLOCKTYPE_D3PCLK1|RCC_CLOCKTYPE_D1PCLK1;
      RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
      RCC_ClkInitStruct.SYSCLKDivider = RCC_SYSCLK_DIV1;
      RCC_ClkInitStruct.AHBCLKDivider = RCC_HCLK_DIV2;
      RCC_ClkInitStruct.APB3CLKDivider = RCC_APB3_DIV2;
      RCC_ClkInitStruct.APB1CLKDivider = RCC_APB1_DIV2;
      RCC_ClkInitStruct.APB2CLKDivider = RCC_APB2_DIV2;
      RCC_ClkInitStruct.APB4CLKDivider = RCC_APB4_DIV2;
    
      if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_4) != HAL_OK)
      {
        Error_Handler();
      }
      PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_USART1|RCC_PERIPHCLK_I2C1
                                  |RCC_PERIPHCLK_FMC;
      PeriphClkInitStruct.PLL2.PLL2M = 4;
      PeriphClkInitStruct.PLL2.PLL2N = 80;
      PeriphClkInitStruct.PLL2.PLL2P = 20;
      PeriphClkInitStruct.PLL2.PLL2Q = 10;
      PeriphClkInitStruct.PLL2.PLL2R = 2;
      PeriphClkInitStruct.PLL2.PLL2RGE = RCC_PLL2VCIRANGE_1;
      PeriphClkInitStruct.PLL2.PLL2VCOSEL = RCC_PLL2VCOWIDE;
      PeriphClkInitStruct.PLL2.PLL2FRACN = 0;
      PeriphClkInitStruct.PLL3.PLL3M = 8;
      PeriphClkInitStruct.PLL3.PLL3N = 128;
      PeriphClkInitStruct.PLL3.PLL3P = 2;
      PeriphClkInitStruct.PLL3.PLL3Q = 2;
      PeriphClkInitStruct.PLL3.PLL3R = 8;
      PeriphClkInitStruct.PLL3.PLL3RGE = RCC_PLL3VCIRANGE_0;
      PeriphClkInitStruct.PLL3.PLL3VCOSEL = RCC_PLL3VCOWIDE;
      PeriphClkInitStruct.PLL3.PLL3FRACN = 0;
      PeriphClkInitStruct.FmcClockSelection = RCC_FMCCLKSOURCE_D1HCLK;
      PeriphClkInitStruct.Usart16ClockSelection = RCC_USART16CLKSOURCE_PLL2;
      PeriphClkInitStruct.I2c123ClockSelection = RCC_I2C123CLKSOURCE_PLL3;
      if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct) != HAL_OK)
      {
        Error_Handler();
      }
      HAL_RCC_MCOConfig(RCC_MCO1, RCC_MCO1SOURCE_PLL1QCLK, RCC_MCODIV_1);
      HAL_RCC_MCOConfig(RCC_MCO2, RCC_MCO2SOURCE_PLL2PCLK, RCC_MCODIV_2);
    	
    	//HAL_EnableCompensationCell();
    }

可以看到HAL\_RCC\_MCOConfig(RCC\_MCO2, RCC\_MCO2SOURCE\_PLL2PCLK, RCC\_MCODIV\_2);是一个只有几个MHz的频率（8M晶振的情况下是4M），相关的MCO引脚配置如下，其中PC9脚就是MCO2，

void MX_GPIO_Init(void)
    {
    
      GPIO_InitTypeDef GPIO_InitStruct = {0};
    
      /* GPIO Ports Clock Enable */
      __HAL_RCC_GPIOE_CLK_ENABLE();
      __HAL_RCC_GPIOF_CLK_ENABLE();
      __HAL_RCC_GPIOH_CLK_ENABLE();
      __HAL_RCC_GPIOC_CLK_ENABLE();
      __HAL_RCC_GPIOA_CLK_ENABLE();
      __HAL_RCC_GPIOB_CLK_ENABLE();
      __HAL_RCC_GPIOG_CLK_ENABLE();
      __HAL_RCC_GPIOD_CLK_ENABLE();
    
      /*Configure GPIO pin : PC9 */
      GPIO_InitStruct.Pin = GPIO_PIN_9;
      GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
      GPIO_InitStruct.Pull = GPIO_NOPULL;
      GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH; //why LOW;
      GPIO_InitStruct.Alternate = GPIO_AF0_MCO;
      HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);
    
      /*Configure GPIO pin : PA8 */
      GPIO_InitStruct.Pin = GPIO_PIN_8;
      GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
      GPIO_InitStruct.Pull = GPIO_NOPULL;
      GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH; //why LOW;
      GPIO_InitStruct.Alternate = GPIO_AF0_MCO;
      HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
    
    }

所以，超出引脚承受范围是不可能的，搜索了一下，发现这里有个贴子碰到的是同样的问题，  
[https://community.st.com/s/question/0D50X0000B8jgmy/problem-with-mco2-from-pll2-stm32h743][https_community.st.com_s_question_0D50X0000B8jgmy_problem-with-mco2-from-pll2-stm32h743]  
里面提到一定要运行这一句：RCCEx\_PLL2\_Config(&(PeriphClkInit->PLL2),DIVIDER\_P\_UPDATE); 如果你选择的外设中没有一个需要这个PLL2P，那么很有可能就不会启动这个DIVIDER\_P\_UPDATE。

赶紧试着改了一下stm32h7xx\_hal\_rcc\_ex.c中的HAL\_RCCEx\_PeriphCLKConfig函数，问题解决！修改后的代码如下，

HAL_StatusTypeDef HAL_RCCEx_PeriphCLKConfig(RCC_PeriphCLKInitTypeDef  *PeriphClkInit)
    {
       。。。。。 原来的代码原封不动。。。。。
    
      // 下面这一行是另外添加的，确保DIVIDER_P_UPDATE会被运行到
      ret = RCCEx_PLL2_Config(&(PeriphClkInit->PLL2),DIVIDER_P_UPDATE);
    	
      if (status == HAL_OK)
      {
        return HAL_OK;
      }
      return HAL_ERROR;
    }

[https_community.st.com_s_question_0D50X0000B8jgmy_problem-with-mco2-from-pll2-stm32h743]: https://community.st.com/s/question/0D50X0000B8jgmy/problem-with-mco2-from-pll2-stm32h743