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RTC can't work because PLL already use

Question asked by starlin lin on Jul 17, 2017
Latest reply on Jul 17, 2017 by Vangelis Fortounas

Dear Sir:

I had reference the PWR_STANDBY_RTC sample code form STM32Cube_FW_L4_V1.8.0

This sample code are work well and wake up about 30 second,

but after move to my code get return fail atif(HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) form SystemClock_Config()


void SystemClock_Config(void)


RCC_OscInitStruct.PLL.PLLR = 2;
RCC_OscInitStruct.PLL.PLLP = 7;
RCC_OscInitStruct.PLL.PLLQ = 4;
if(HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
// return here.


after check, find is because PLL already used?

/* Check if the PLL is used as system clock or not */


return HAL_ERROR;

I have reference this web say need turn off some content of SystemInit()

STM32如何使用内部HSI作为PLL的系统时钟源 - 海纳百川 - 面包板社区 

but still don't work, then how to use PLL and let SystemClock_Config?

Thx for your answer.