Question

stm32 唤醒后配置什么

Answer 1

Hi 大家，
这几天在调试stm32的低功耗，采用rtc的alarm唤醒，在唤醒之前所用的外设有uart，TIM2.当唤醒之后，首先我从新配置了时钟：代码

ErrorStatus HSEStartUpStatus;

//turn on HSE
RCC_HSEConfig(RCC_HSE_ON);

//Wait till HSE is ready and if Time out is reached exit
HSEStartUpStatus = RCC_WaitForHSEStartUp();
if(HSEStartUpStatus == SUCCESS)
{
/* Enable Prefetch Buffer */
FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable);

/* Flash 2 wait state */
FLASH_SetLatency(FLASH_Latency_2);

/* HCLK = SYSCLK */
RCC_HCLKConfig(RCC_SYSCLK_Div1);

/* PCLK2 = HCLK */
RCC_PCLK2Config(RCC_HCLK_Div1);

/* PCLK1 = HCLK/2 */
RCC_PCLK1Config(RCC_HCLK_Div2);

/* PLLCLK = 8MHz * 9 = 72 MHz */
RCC_PLLConfig(RCC_PLLSource_HSE_Div1, RCC_PLLMul_9);

//enable PLL
RCC_PLLCmd(ENABLE);

//Wait till PLL is ready
while(RCC_GetFlagStatus(RCC_FLAG_PLLRDY) == RESET)
{}

//Select PLL as system clock source
RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK);

//Wait till PLL is used as system clock source
while(RCC_GetSYSCLKSource() != 0x08)
{}
}

这段代码应该没问题，以防万一，先贴出来。