a = SBUF;
recive=2;
switch(recive)
{
case 0:printf("停止\r\n");break;
case 1:printf("3\r\n");break;
case 2:printf("2\r\n");break;
case 3:printf("1\r\n");break;
default: break;
}
RI=0;
}
}
//====================================================================
//主程序
void main()
{