2025-07-17 9:55 AM
Hi everyone.
Im using the nucleo-h743zi2 and im facing the following issue:
When trying to printf using redirect to usart3 with the following clock settings:
/**
* @brief System Clock Configuration
* The system Clock is configured as follow :
* System Clock source = PLL (HSE BYPASS)
* SYSCLK(Hz) = 400000000 (CPU Clock)
* HCLK(Hz) = 200000000 (AXI and AHBs Clock)
* AHB Prescaler = 2
* D1 APB3 Prescaler = 2 (APB3 Clock 100MHz)
* D2 APB1 Prescaler = 2 (APB1 Clock 100MHz)
* D2 APB2 Prescaler = 2 (APB2 Clock 100MHz)
* D3 APB4 Prescaler = 2 (APB4 Clock 100MHz)
* HSE Frequency(Hz) = 8000000
* PLL_M = 4
* PLL_N = 400
* PLL_P = 2
* PLL_Q = 4
* PLL_R = 2
* VDD(V) = 3.3
* Flash Latency(WS) = 4
* @PAram None
* @retval None
*/
static void SystemClock_Config(void)
{
RCC_ClkInitTypeDef RCC_ClkInitStruct;
RCC_OscInitTypeDef RCC_OscInitStruct;
HAL_StatusTypeDef ret = HAL_OK;
/* The voltage scaling allows optimizing the power consumption when the device is
clocked below the maximum system frequency, to update the voltage scaling value
regarding system frequency refer to product datasheet. */
__HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);
while(!__HAL_PWR_GET_FLAG(PWR_FLAG_VOSRDY)) {}
/* Enable D2 domain SRAM3 Clock (0x30040000 AXI)*/
__HAL_RCC_D2SRAM3_CLK_ENABLE();
/* Enable HSE Oscillator and activate PLL with HSE as source */
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
RCC_OscInitStruct.HSEState = RCC_HSE_BYPASS;
RCC_OscInitStruct.HSIState = RCC_HSI_OFF;
RCC_OscInitStruct.CSIState = RCC_CSI_OFF;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
RCC_OscInitStruct.PLL.PLLM = 4;
RCC_OscInitStruct.PLL.PLLN = 400;
RCC_OscInitStruct.PLL.PLLFRACN = 0;
RCC_OscInitStruct.PLL.PLLP = 2;
RCC_OscInitStruct.PLL.PLLR = 2;
RCC_OscInitStruct.PLL.PLLQ = 4;
RCC_OscInitStruct.PLL.PLLVCOSEL = RCC_PLL1VCOWIDE;
RCC_OscInitStruct.PLL.PLLRGE = RCC_PLL1VCIRANGE_1;
ret = HAL_RCC_OscConfig(&RCC_OscInitStruct);
if(ret != HAL_OK)
{
while(1);
}
/* Select PLL as system clock source and configure bus clocks dividers */
RCC_ClkInitStruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_D1PCLK1 | RCC_CLOCKTYPE_PCLK1 | \
RCC_CLOCKTYPE_PCLK2 | RCC_CLOCKTYPE_D3PCLK1);
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;
ret = HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_4);
if(ret != HAL_OK)
{
while(1);
}
}
Only works when im doing firmware update to 5MHZ HSE.
I tried to configure a setting trough stm32cubeMX with 8MHZ as input and 400MHZ as Sysclk but got only garbge when printing.
I add this code + the stm32h..msp file to my src to the lwip_netconn_rtos example
Any ideas or explaination would be awosome thx!
2025-07-17 10:08 AM
> RCC_HSE_BYPASS
The clock rate used in the calculations will need to match the clock rate coming in. You do this by setting HSE_VALUE in the code, or on the left in the IOC clock tab.
The clock rate coming in from the st-link is typically 8 MHz, but this can also be changed via the firmware upgrade tool.
2025-07-17 10:14 AM
Yea thats the weird thing is that when trying to config with 5MHZ input +400MHZ sysclk in stm32cubeMX and using these settings the printf is outputting garbage.
And when using 5MHZ and the settings i sent above it output correctly🥲
Any ideas what could make this happen?
Maybe other settings in this example that i miss? https://github.com/STMicroelectronics/STM32CubeH7/tree/master/Projects%2FNUCLEO-H743ZI%2FApplications%2FLwIP%2FLwIP_HTTP_Server_Netconn_RTOS%2FSrc
2025-07-17 10:21 AM
Is your st-link clock set to output 5 MHz? Sounds like it is.
Open stm32cubeprogrammer, go into firmware upgrade.
2025-07-17 10:26 AM - edited 2025-07-17 10:30 AM
Sorry if i was not clear,and thanks for your quick respone.
When configure:
STLINK V3 CLOCK = 5MHZ HSE with the following settings:
/**
* @brief System Clock Configuration
* The system Clock is configured as follow :
* System Clock source = PLL (HSE BYPASS)
* SYSCLK(Hz) = 400000000 (CPU Clock)
* HCLK(Hz) = 200000000 (AXI and AHBs Clock)
* AHB Prescaler = 2
* D1 APB3 Prescaler = 2 (APB3 Clock 100MHz)
* D2 APB1 Prescaler = 2 (APB1 Clock 100MHz)
* D2 APB2 Prescaler = 2 (APB2 Clock 100MHz)
* D3 APB4 Prescaler = 2 (APB4 Clock 100MHz)
* HSE Frequency(Hz) = 8000000
* PLL_M = 4
* PLL_N = 400
* PLL_P = 2
* PLL_Q = 4
* PLL_R = 2
* VDD(V) = 3.3
* Flash Latency(WS) = 4
* None
* @retval None
*/
static void SystemClock_Config(void)
{
RCC_ClkInitTypeDef RCC_ClkInitStruct;
RCC_OscInitTypeDef RCC_OscInitStruct;
HAL_StatusTypeDef ret = HAL_OK;
/* The voltage scaling allows optimizing the power consumption when the device is
clocked below the maximum system frequency, to update the voltage scaling value
regarding system frequency refer to product datasheet. */
__HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);
while(!__HAL_PWR_GET_FLAG(PWR_FLAG_VOSRDY)) {}
/* Enable D2 domain SRAM3 Clock (0x30040000 AXI)*/
__HAL_RCC_D2SRAM3_CLK_ENABLE();
/* Enable HSE Oscillator and activate PLL with HSE as source */
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
RCC_OscInitStruct.HSEState = RCC_HSE_BYPASS;
RCC_OscInitStruct.HSIState = RCC_HSI_OFF;
RCC_OscInitStruct.CSIState = RCC_CSI_OFF;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
RCC_OscInitStruct.PLL.PLLM = 4;
RCC_OscInitStruct.PLL.PLLN = 400;
RCC_OscInitStruct.PLL.PLLFRACN = 0;
RCC_OscInitStruct.PLL.PLLP = 2;
RCC_OscInitStruct.PLL.PLLR = 2;
RCC_OscInitStruct.PLL.PLLQ = 4;
RCC_OscInitStruct.PLL.PLLVCOSEL = RCC_PLL1VCOWIDE;
RCC_OscInitStruct.PLL.PLLRGE = RCC_PLL1VCIRANGE_1;
ret = HAL_RCC_OscConfig(&RCC_OscInitStruct);
if(ret != HAL_OK)
{
while(1);
}
/* Select PLL as system clock source and configure bus clocks dividers */
RCC_ClkInitStruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_D1PCLK1 | RCC_CLOCKTYPE_PCLK1 | \
RCC_CLOCKTYPE_PCLK2 | RCC_CLOCKTYPE_D3PCLK1);
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;
ret = HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_4);
if(ret != HAL_OK)
{
while(1);
}
}
The printf works - even though its configured to 8MHZ in code but 5MHZ in STLINK.
But when trying to use 5MHZ HSE of STLINK after firmware update
And code that generated by STM32cubeMX with 5MHZ as input frequenccy and 400MHZ as clock.
The printf doesnt work and outputs garbage.
Any ideas?
2025-07-17 12:04 PM
Is HSE_VALUE set to 5000000?
Comments about the clock setup are nice, but that's not what the code actually uses. Perhaps include your IOC file.
If you toggle a pin at 1 Hz (HAL_Delay(1000) between calls), does the timing match up?
2025-07-17 1:27 PM
Its looks like its 8000000:
/* ########################## Oscillator Values adaptation ####################*/
/**
* @brief Adjust the value of External High Speed oscillator (HSE) used in your application.
* This value is used by the RCC HAL module to compute the system frequency
* (when HSE is used as system clock source, directly or through the PLL).
*/
#if !defined (HSE_VALUE)
#define HSE_VALUE ((uint32_t)8000000) /*!< Value of the External oscillator in Hz */
#endif /* HSE_VALUE */
in the STM32H7xx_HAL_CONF_H file.
So l got 2 questions:
1. How did it even worked when I used 5MHZ as input in the ST-LINKV3 firrmware update?
with the following settings:
/**
* @brief System Clock Configuration
* The system Clock is configured as follow :
* System Clock source = PLL (HSE BYPASS)
* SYSCLK(Hz) = 400000000 (CPU Clock)
* HCLK(Hz) = 200000000 (AXI and AHBs Clock)
* AHB Prescaler = 2
* D1 APB3 Prescaler = 2 (APB3 Clock 100MHz)
* D2 APB1 Prescaler = 2 (APB1 Clock 100MHz)
* D2 APB2 Prescaler = 2 (APB2 Clock 100MHz)
* D3 APB4 Prescaler = 2 (APB4 Clock 100MHz)
* HSE Frequency(Hz) = 8000000
* PLL_M = 4
* PLL_N = 400
* PLL_P = 2
* PLL_Q = 4
* PLL_R = 2
* VDD(V) = 3.3
* Flash Latency(WS) = 4
* None
* @retval None
*/
static void SystemClock_Config(void)
{
RCC_ClkInitTypeDef RCC_ClkInitStruct;
RCC_OscInitTypeDef RCC_OscInitStruct;
HAL_StatusTypeDef ret = HAL_OK;
/* The voltage scaling allows optimizing the power consumption when the device is
clocked below the maximum system frequency, to update the voltage scaling value
regarding system frequency refer to product datasheet. */
__HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);
while(!__HAL_PWR_GET_FLAG(PWR_FLAG_VOSRDY)) {}
/* Enable D2 domain SRAM3 Clock (0x30040000 AXI)*/
__HAL_RCC_D2SRAM3_CLK_ENABLE();
/* Enable HSE Oscillator and activate PLL with HSE as source */
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
RCC_OscInitStruct.HSEState = RCC_HSE_BYPASS;
RCC_OscInitStruct.HSIState = RCC_HSI_OFF;
RCC_OscInitStruct.CSIState = RCC_CSI_OFF;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
RCC_OscInitStruct.PLL.PLLM = 4;
RCC_OscInitStruct.PLL.PLLN = 400;
RCC_OscInitStruct.PLL.PLLFRACN = 0;
RCC_OscInitStruct.PLL.PLLP = 2;
RCC_OscInitStruct.PLL.PLLR = 2;
RCC_OscInitStruct.PLL.PLLQ = 4;
RCC_OscInitStruct.PLL.PLLVCOSEL = RCC_PLL1VCOWIDE;
RCC_OscInitStruct.PLL.PLLRGE = RCC_PLL1VCIRANGE_1;
ret = HAL_RCC_OscConfig(&RCC_OscInitStruct);
if(ret != HAL_OK)
{
while(1);
}
/* Select PLL as system clock source and configure bus clocks dividers */
RCC_ClkInitStruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_D1PCLK1 | RCC_CLOCKTYPE_PCLK1 | \
RCC_CLOCKTYPE_PCLK2 | RCC_CLOCKTYPE_D3PCLK1);
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;
ret = HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_4);
if(ret != HAL_OK)
{
while(1);
}
}
2. If i want to use the 5MHZ update in the ST-LINKV3 I need to change the
/* ########################## Oscillator Values adaptation ####################*/
/**
* @brief Adjust the value of External High Speed oscillator (HSE) used in your application.
* This value is used by the RCC HAL module to compute the system frequency
* (when HSE is used as system clock source, directly or through the PLL).
*/
#if !defined (HSE_VALUE)
#define HSE_VALUE ((uint32_t)5000000) /*!< Value of the External oscillator in Hz */
#endif /* HSE_VALUE */
and set the following settings in clock tree: ?
Thanks alot for your help and I hope this post will help more ppls (:
2025-07-17 1:28 PM - edited 2025-07-17 1:39 PM
The problem is that the bypass HSE clock source going from the ST-LINK has two options: the default is 8.0 MHz but its source is HSI - which is imprecise. If you want the precise HSE - then the frequency will be 25/3 = 8.3(3).
With the latest firmware you can select also HSE/5.
2025-07-17 1:35 PM
You can also use 5MHZ HSE -
https://community.st.com/t5/stm32-mcus/how-to-use-stlink-v3-mco-output-on-nucleo-boards-as-a-precise/ta-p/723361
I Hope it will help you also (:
with this can you look at my 2 questions above please?
@Pavel A.
Thanks (:
2025-07-17 1:45 PM - edited 2025-07-17 1:47 PM
Is HSE_VALUE defined in the Eclipse project preprocessor defines? Defining only in hal_conf.h is not enough IIRC. I don't remember why exactly.
Yep I stand corrected, thanks.