芯嵌stm32上电，LED灯闪烁表明系统正常运行。按下按键K1或K2，进入待机模式，LED灯灭掉。 直到按下WKUP按键，LED灯重新闪烁，说明从待机模式重新回到正常运行状态。 -Core embedded on stm32 power, LED light flashes to indicate normal system operation. Press the key K1 or K2, enter standby mode, LED lights burn out. WKUP u