communication.c

通过串口升级mega8的自编程例子原码

#include "define.h"
void rx_data(void)  //接收报文头并判断 /接收所有字节并验证
{

	unsigned char rx_data;
	if (write_timeover>0)
	{
	    while(rx_counter>0)
    	{
        	getchar ();
		}
	}
    while(rx_counter>0)
    {
        rx_data = getchar ();
		if (rx_head < 3)     //判断接收缓冲器是否有数据
		{
			if (rx_data == 0x76)
			{ 
				rx_head++;    //判3个报文头
				rx_timeover = 2 ;	//超时保护启动 
			}
	   		else 
			{
				rx_head = 0;  
				rx_timeover = 0 ;	//超时保护关闭  
			}
		}  
        else if ( rx_head >= 3 )
		{                        
			rx_timeover = 2;	//超时保护启动 
			if (rx_length == 0)		//接收报文长度  
			{
				rx_buffer_index = 1;
				rt_buffer[0]=rx_data;
				if (rx_data==0x11)
					rx_length = 0x41;
				else if (rx_data==0x12)
					rx_length = 0x01;	
				else	//
				{
					rx_head = 0;
					rx_length = 0;
					rx_timeover = 0;
				}
			}
			else if (rx_length>0)	//接收报文长度后的字节                 
			{
		 		rt_buffer[rx_buffer_index] = rx_data;		
		 		rx_buffer_index++ ;
		 		rx_length--;
		 		if (rx_length==0)
		 		{
		    		b_rx_end = 1;
					rx_head = 0;
 					rx_length = 0;
				    rx_timeover = 0;  //超时保护关闭
			    } 
		 	}
		 }                   
	}
}              
void rx_access(void)  //处理数据
{
	unsigned char a,b,i;
	b_tx_sign = 0;
	tx_code = rt_buffer[0];
	switch(tx_code)
	{
 		case 0x11:	//写入一页
			write_timeover=100;
			step=1;
			rt_buffer[0]=0x91;
   			break;
		case 0x12:      //读出一页
			b_tx_sign=1;
			rt_buffer[0]=0x92;
			a=rt_buffer[1];
			b=a&0x7f;
			b>>=2;
			a<<=6;
			for (i=0;i<64;i++)
			{
				rt_buffer[2+i]=read_flash(a+i,b);
			}
			break;
		default:
			b_tx_sign=0;
			break;
	}
}
void tx_data(void)  //发送字节 应答
{  
	unsigned char i,j=0;
	putchar(0x76);
	putchar(0x76);
	putchar(0x76);
	if (rt_buffer[0]==0x91)
		j=1;
	else if (rt_buffer[0]==0x92)
		j=0x42;
	for (i=0;i<j;i++)
	{
		putchar(rt_buffer[i]);
	}
}