[mw_shl_code=c,true]void RCC_Init_t(void) { RCC->CFGR &= ~0x0003; delay(10); RCC->CR &= ~(1<<24); RCC->LLCFGR &= ~0x7fff; RCC->LLCFGR |= 0x8; RCC->LLCFGR |= (168<<6); RCC->CR |= (1<<24); delay(10); RCC->CFGR |= 0x0002; }[/mw_shl_code]
这是我的时钟初始化程序 [mw_shl_code=c,true]int main(void) { RCC_Init_t(); RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOE, ENABLE); GPIOI_Init(); while(1) { i++; GPIOE->ODR = ((i%2)<<2); } }[/mw_shl_code]
while循环里面只是将引脚高低点低平翻转，结果输出的只有3MHz。这是怎么回事。难道系统时钟不指while里面程序运行吗？