串口编程--接收PC发过来的字符串,回发字符串.发送期间中断控制LED灯闪烁 采用外部晶振22.1184MHz 使用定时器1,方式2产生波特率,SMOD = 0或者1 定时器初值X=256-SYSCLK*(SMOD+1)(BAUDRATE*384) -Serial Programming -- receiving PC sent the string, the string back. During this interruption control LED lights exter