usart使用.c

使用mega8的USART与计算机通信

//ICC-AVR application builder : 1980-1-4 4:49:58
// Target : M8
// Crystal: 1.0000Mhz

#include <iom8v.h>
#include <macros.h>
unsigned char f[6]={0x01,0x02,0x03,0x04,0x05,0x00};

void port_init(void)
{
 PORTB = 0xFF;
 DDRB  = 0x00;
 PORTC = 0x7F; //m103 output only
 DDRC  = 0x00;
 PORTD = 0xFF;
 DDRD  = 0x02;
}

//UART0 initialisation
// desired baud rate: 9600
// actual: baud rate:9615 (0.2%)
// char size: 8 bit
// parity: Disabled
void uart0_init(void)
{
 UCSRB = 0x00; //disable while setting baud rate
 UCSRA = 0x02;//倍速
 UCSRC = 0x86;//写UCSRAC,XCK下降沿采样，异步
 UBRRL = 0x0C; //set baud rate lo
 UBRRH = 0x00; //set baud rate hi
 UCSRB = 0x98;//接收结束中断使能
 }
 /*字符输入函数*/         
/*unsigned char getchar(void) 
{ 
       while(!(UCSRA& (1<<RXC))); 
       return UDR; 
} 
*///UART0 发送一个字节
void put_char(unsigned char d)       
{/* 等待发送缓冲器为空 */
while ( !( UCSRA & (1<<UDRE)));
/* 将数据放入缓冲器，发送数据 */
  UDR=d;
  //while(!(UCSRA&0x40));        //等待TXC置位
  //UCSRA|=0x40;                 //写1清零
}
 //字符输入函数
void put_s(unsigned char *s) 
{  
      while (*s) 
      { 
           put_char(*s); 
           s++; 
       }         
}

#pragma interrupt_handler uart0_rx_isr:12
void uart0_rx_isr(void)//接收中断RXC置1时中断
{
put_char(UDR);//接收完发送短信
 
 //uart has received a character in UDR
}

//call this routine to initialise all peripherals
void init_devices(void)
{
 //stop errant interrupts until set up
 CLI(); //disable all interrupts
 port_init();
 uart0_init();

 MCUCR = 0x00;
 GICR  = 0x00;
 TIMSK = 0x00; //timer interrupt sources
 SEI(); //re-enable interrupts
 //all peripherals are now initialised
}
void delay_us(int time)
	 {     
  	  do
	  	{
		 time--;
		}	
  	  while (time>1);
	 }	   
void delay_ms(unsigned int time)
	 {
	   while(time!=0)
	  	  {		
		   delay_us(30);
		   time--;
		  }
	 } 

void main()
{int i;
 init_devices();
 /*put_s("hello donkey!");
 put_char(0x0a);
 put_char(0x0d);
 put_s("i love you");*/
 while(1)
 {
 for(i=0;i<6;i++)
 {
 put_char(f[i]);
 }//显示数字时，调proteus里面黑屏右键hex display mode
 //while(1);
 delay_ms(100);
 }
 }