PC和ATMEGA128串口通信

#include
#define RXEN0 4
#define TXEN0 3
#define RXCIE0 7
#define UDRE0 5
#define UCSZ00 1
#define UCSZ01 2
#define UCSZ02 2
#define RXC0 7
char str[20];

unsigned char in;
void Uar_init(void);
void COM_send(void);

interrupt[19] voiduart0(void)
{
bit flag=1;
str[in]=UDR0;
if(str[in]==$) //$为停止标志
{
UCSR0B&=~(1< str[in]=;
COM_send(); //发送接受的字符串
in=0;

flag=0;
UCSR0B|=(1< }
if(flag)
in++;

}

void Uar_init(void)
{

in=0;
UCSR0B=(1< UBRR0L=0x2f;
UBRR0H=0x00;
UCSR0C=(1<

}

void COM_send(void)
{
unsigned char point=0;
while(str[point]!=)
{

while(!(UCSR0A&(1< UDR0=str[point];
point++;
}
}

void main(void)
{

Uar_init();

#asm("sei");//全局中断开启

while(1);

}