HAL_UART_Init --> HAL_RCCEx_PeriphCLKConfig --> HardFault_Handler

[Sergei2]

MCU STM32H503KBU

internal clock  64 MHz

During a UART restart,
the HAL_UART_Init function calls
HAL_RCCEx_PeriphCLKConfig, which results in a HardFault_Handler

void UART_Set_BaudRate(UART_HandleTypeDef *huart, uint32_t BaudRate) 
{
	if (HAL_UART_DeInit(huart)!= HAL_OK)
	{
	Error_Handler();
	}

	huart->Instance = USART1;
	huart->Init.BaudRate = BaudRate;
	huart->Init.WordLength = UART_WORDLENGTH_8B;
	huart->Init.StopBits = UART_STOPBITS_1;
	huart->Init.Parity = UART_PARITY_NONE;
	huart->Init.Mode = UART_MODE_TX_RX;
	huart->Init.HwFlowCtl = UART_HWCONTROL_NONE;
	huart->Init.OverSampling = UART_OVERSAMPLING_16;
	huart->Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE;
	huart->Init.ClockPrescaler = UART_PRESCALER_DIV1;
	huart->AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;

	if (HAL_UART_Init(huart) != HAL_OK)
	{
	Error_Handler();
	}

	if (HAL_UART_Receive_IT( OW.huart, &uart_temp, 1) != HAL_OK)
	 Error_Handler();
}

If you disable the HAL_UART_DeInit function, everything works.

 What could be the problem?

[mƎALLEm]

Hello,

Not clear what do you mean by "During a UART restart".

+ in your code:

if (HAL_UART_Receive_IT( OW.huart, &uart_temp, 1) != HAL_OK)

What is that OW here?

You need to use the already used UART instance: huart

if (HAL_UART_Receive_IT(huart, &uart_temp, 1) != HAL_OK)

[Sergei2]

UART reboot is done to clear possible errors

As far as I understand, there's no direct function for this in HAL, so I use

HAL_UART_DeInit
HAL_UART_Init

about OW ,yes, it's my mistake. This is a global variable that is passed to this function.

OW.huart = &huart1;

But that's not a problem...
The first initialization goes fine

MX_USART1_UART_Init();

but repeating it after HAL_UART_DeInit causes an error

[mƎALLEm]

How to debug a HardFault on an Arm® Cortex®-M STM32