Hello Everyone
I encounter a problem with clock initialization for STM32H753V for peripheral clocks.
I found a similar thread periphcommonclockconfig-when-adc-clocked-by-pll3 dealing with a similar thing, but mine is different:
I have a very simple project with STM32H753VITx via CubeIDE 1.16.0 using CubeMX 6.12.1
I only uses usart2 to transmit something.
USART2 is the only one using PLL2.
Because it is the only peripheral using PLL2, there is no PerpheralCommonClockConfig. The Clock is initialized within HAL_UART_MspInit:
void HAL_UART_MspInit(UART_HandleTypeDef* uartHandle)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
RCC_PeriphCLKInitTypeDef PeriphClkInitStruct = {0};
if(uartHandle->Instance==USART2)
{
/* USER CODE BEGIN USART2_MspInit 0 */
/* USER CODE END USART2_MspInit 0 */
/** Initializes the peripherals clock
*/
PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_USART2;
PeriphClkInitStruct.Usart234578ClockSelection = RCC_USART234578CLKSOURCE_PLL2;
if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct) != HAL_OK)
{
Error_Handler();
}
/* USART2 clock enable */
__HAL_RCC_USART2_CLK_ENABLE();
__HAL_RCC_GPIOD_CLK_ENABLE();
The clock configuration for PLL2 is missing all settings for the prescalers and PLLs
If I enable something else also using PLL2 (like CAN), PerpheralCommonClockConfig is generated and it looks like this:
void PeriphCommonClock_Config(void)
{
RCC_PeriphCLKInitTypeDef PeriphClkInitStruct = {0};
/** Initializes the peripherals clock
*/
PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_ADC|RCC_PERIPHCLK_FDCAN
|RCC_PERIPHCLK_USART2;
PeriphClkInitStruct.PLL2.PLL2M = 2;
PeriphClkInitStruct.PLL2.PLL2N = 40;
PeriphClkInitStruct.PLL2.PLL2P = 8;
PeriphClkInitStruct.PLL2.PLL2Q = 6;
PeriphClkInitStruct.PLL2.PLL2R = 2;
PeriphClkInitStruct.PLL2.PLL2RGE = RCC_PLL2VCIRANGE_2;
PeriphClkInitStruct.PLL2.PLL2VCOSEL = RCC_PLL2VCOWIDE;
PeriphClkInitStruct.PLL2.PLL2FRACN = 0;
PeriphClkInitStruct.FdcanClockSelection = RCC_FDCANCLKSOURCE_PLL2;
PeriphClkInitStruct.Usart234578ClockSelection = RCC_USART234578CLKSOURCE_PLL2;
PeriphClkInitStruct.AdcClockSelection = RCC_ADCCLKSOURCE_PLL2;
if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct) != HAL_OK)
{
Error_Handler();
}
This one correctly contains all PLL prescaler and multiplier settings.
Back to the version from before, USART2 being the only one using PLL2
If I add this piece of code manually:
Then the UART gets the correct clock and is working fine.
It looks like a bug to me in CubeMX 6.12.1.
I either config the PLL manually myself, or I make sure, that there are always more than one peripheral using PLL2
Please comment. Is this a bug?
IOC-file attached
Thank you
Johannes
