void Usart() interrupt 4
{
u8 receiveData;
receiveData=SBUF;//??????????????
RI = 0;//????????ж???λ
switch(receiveData)
{
case 'A':RIGHT();break;
case 'B':GO();break;
case 'C':LEFT();break;
case 'D':BACK();break;
case 'E':STOP();break;
}
TI=0; //????????????λ
}