那个是官方库里的函数，是这样定义的：
/**
* @brief This function returns the frequencies of different on chip clocks.
* @param None
* @retval the master clock frequency
*/
uint32_t CLK_GetClockFreq(void)
{
uint32_t clockfrequency = 0;
CLK_Source_TypeDef clocksource = CLK_SOURCE_HSI;
uint8_t tmp = 0, presc = 0;
/* Get CLK source. */
clocksource = (CLK_Source_TypeDef)CLK->CMSR;
if (clocksource == CLK_SOURCE_HSI)
{
tmp = (uint8_t)(CLK->CKDIVR & CLK_CKDIVR_HSIDIV);
tmp = (uint8_t)(tmp >> 3);
presc = HSIDivFactor[tmp];
clockfrequency = HSI_VALUE / presc;
}
else if ( clocksource == CLK_SOURCE_LSI)
{
clockfrequency = LSI_VALUE;
}
else
{
clockfrequency = HSE_VALUE;
}
return((uint32_t)clockfrequency);
}
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楼主
