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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 starlin lin

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.

while(1);
}

after check, find is because PLL already used?

/* Check if the PLL is used as system clock or not */
if(__HAL_RCC_GET_SYSCLK_SOURCE() != RCC_CFGR_SWS_PLL)
{

.......

else
{
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.

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