stm32h755 Clock setup: HAL_RCC_ClockConfig returns error.

[Mark12]

Hi all,

I am having issues with Clock setup for Stm32h755. Especially regarding the M4 core. Currently, I only run the M4 core. The M7 core has no valid firmware. Is that even a supported mode?

I try to setup a rather basic clock setup but the setup keeps failing at the call: HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_4), which will return an not ok return value.

I also tried using HSI and other different setups. But it seems the keep failing in the same way. Interestingly... When I simply ignore the error. Then most stuff seems to work just fine. I got ADC, SPI, Timers working. However, I am not sure where the issue is with the clock configuration.

The entire clock setup: 

static void SystemClock_Config(void) {
 RCC_OscInitTypeDef RCC_OscInitStruct = {0};
 RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

 __HAL_RCC_SYSCFG_CLK_ENABLE();

 RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI | RCC_OSCILLATORTYPE_HSE;
 RCC_OscInitStruct.HSEState = RCC_HSE_ON;
 RCC_OscInitStruct.HSIState = RCC_HSI_ON;
 RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
 RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
 RCC_OscInitStruct.PLL.PLLM = 5;
 RCC_OscInitStruct.PLL.PLLN = 192;
 RCC_OscInitStruct.PLL.PLLP = 2;
 RCC_OscInitStruct.PLL.PLLQ = 2;
 RCC_OscInitStruct.PLL.PLLR = 2;
 RCC_OscInitStruct.PLL.PLLRGE = RCC_PLL1VCIRANGE_2;
 RCC_OscInitStruct.PLL.PLLVCOSEL = RCC_PLL1VCOWIDE;
 RCC_OscInitStruct.PLL.PLLFRACN = 0;
 if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) {
 // print error
 }

 /** Initializes the CPU, AHB and APB buses 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) {
 // print error
 }
}

Best regards

Mark

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Edited to apply proper source code formatting - please see How to insert source code for future reference.

[TDK]

The clock failing to start can suggest the HSE design is not correct. Perhaps incorrect load caps.

Guidelines for oscillator design on STM8AF/AL/S and STM32 MCUs/MPUs - Application note

 

M4 having no firmware is fine. You can set option bytes such that the M4 core doesn't boot, but it's not an issue here.

[Andrew Neil]

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@Mark12 wrote:

the call: HAL_RCC_ClockConfig( &RCC_ClkInitStruct, FLASH_LATENCY_4 ), which will return an not ok return value..

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Have you tried stepping into that function to see where & why, exactly, it is failing?

[Mark12]

Hi Andrew,

I stepped inside and it seems to fail in:

__weak HAL_StatusTypeDef HAL_InitTick(uint32_t TickPriority)

 

more precisely in this check:

/* Configure the SysTick IRQ priority */
if (TickPriority < (1UL << __NVIC_PRIO_BITS))
{
 HAL_NVIC_SetPriority(SysTick_IRQn, TickPriority, 0U);
 uwTickPrio = TickPriority;
}
else
{
 // will return ERROR here
 return HAL_ERROR;
}

 

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Edited to apply proper source code formatting - please see How to insert source code for future reference.

[mƎALLEm]

Hello,

Which board are you using? Nucleo board?

If it's the case, you need to set HSE in Bypass mode as the clock source is provided from the STLINK (STLINK_MCO) and there is no crystal on the board:

 

[Mark12]

Hi,

yes. I am on a nucleo board. I tried setting HSE_Bypass but it didnt change the behavior. The Config method fails on the method 

HAL_InitTick

Because of what seems to be an invalid TickPriority of "16" which is somehow present. 

 

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Edited to apply proper source code formatting - please see How to insert source code for future reference.

[TDK]

16 is not a valid priority. Change it to 15 or less.

 

Include your IOC file if you're having trouble.