[mw_shl_code=c,true] void SystemInit (void)
{
/* Set HSION bit */
RCC->CR |= (uint32_t)0x00000001;
RCC->CFGR |= (uint32_t)RCC_CFGR_PLLSRC_HSI_Div2;
//PLLCLK=8/2*12=48M
RCC->CFGR |= (uint32_t)RCC_CFGR_PLLMULL12;
/* HCLK = SYSCLK/4 */
RCC->CFGR |= (uint32_t)RCC_CFGR_HPRE_DIV4;
/* Enable PLL */
RCC->CR |= RCC_CR_PLLON;
/* Wait till PLL is ready */
while((RCC->CR & RCC_CR_PLLRDY) == 0)
{
}
/* Select PLL as system clock source */
RCC->CFGR &= (uint32_t)((uint32_t)~(RCC_CFGR_SW));
RCC->CFGR |= (uint32_t)RCC_CFGR_SW_PLL;
/* Wait till PLL is used as system clock source */
while ((RCC->CFGR & (uint32_t)RCC_CFGR_SWS) != (uint32_t)0x08)
{
}
}[/mw_shl_code]
用keil改的,使用库函数,修改SystemLint,应该满足第一个要求。希望对你有用。
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