m16-12.i

AVR单片机之间多机通信（通信方式采用的中断进行）

//从机12
// CodeVisionAVR C Compiler
// (C) 1998-2001 Pavel Haiduc, HP InfoTech S.R.L.

// I/O registers definitions for the ATmega16


#pragma used+
#pragma used+
sfrb TWBR=0;
sfrb TWSR=1;
sfrb TWAR=2;
sfrb TWDR=3;
sfrb ADCL=4;
sfrb ADCH=5;
sfrw ADCW=4;      // 16 bit access
sfrb ADCSRA=6;
sfrb ADMUX=7;
sfrb ACSR=8;
sfrb UBRRL=9;
sfrb UCSRB=0xa;
sfrb UCSRA=0xb;
sfrb UDR=0xc;
sfrb SPCR=0xd;
sfrb SPSR=0xe;
sfrb SPDR=0xf;
sfrb PIND=0x10;
sfrb DDRD=0x11;
sfrb PORTD=0x12;
sfrb PINC=0x13;
sfrb DDRC=0x14;
sfrb PORTC=0x15;
sfrb PINB=0x16;
sfrb DDRB=0x17;
sfrb PORTB=0x18;
sfrb PINA=0x19;
sfrb DDRA=0x1a;
sfrb PORTA=0x1b;
sfrb EECR=0x1c;
sfrb EEDR=0x1d;
sfrb EEARL=0x1e;
sfrb EEARH=0x1f;
sfrw EEAR=0x1e;   // 16 bit access
sfrb UBRRH=0x20;
sfrb UCSRC=0X20;
sfrb WDTCR=0x21;
sfrb ASSR=0x22;
sfrb OCR2=0x23;
sfrb TCNT2=0x24;
sfrb TCCR2=0x25;
sfrb ICR1L=0x26;
sfrb ICR1H=0x27;
sfrb OCR1BL=0x28;
sfrb OCR1BH=0x29;
sfrw OCR1B=0x28;  // 16 bit access
sfrb OCR1AL=0x2a;
sfrb OCR1AH=0x2b;
sfrw OCR1A=0x2a;  // 16 bit access
sfrb TCNT1L=0x2c;
sfrb TCNT1H=0x2d;
sfrw TCNT1=0x2c;  // 16 bit access
sfrb TCCR1B=0x2e;
sfrb TCCR1A=0x2f;
sfrb SFIOR=0x30;
sfrb OSCCAL=0x31;
sfrb OCDR=0x31;
sfrb TCNT0=0x32;
sfrb TCCR0=0x33;
sfrb MCUCSR=0x34;
sfrb MCUCR=0x35;
sfrb TWCR=0x36;
sfrb SPMCR=0x37;
sfrb TIFR=0x38;
sfrb TIMSK=0x39;
sfrb GIFR=0x3a;
sfrb GICR=0x3b;
sfrb OCR0=0X3c;
sfrb SPL=0x3d;
sfrb SPH=0x3e;
sfrb SREG=0x3f;
#pragma used-

// Interrupt vectors definitions


// Needed by the power management functions (sleep.h)
#asm
	#ifndef __SLEEP_DEFINED__
	#define __SLEEP_DEFINED__
	.EQU __se_bit=0x40
	.EQU __sm_mask=0xB0
	.EQU __sm_powerdown=0x20
	.EQU __sm_powersave=0x30
	.EQU __sm_standby=0xA0
	.EQU __sm_ext_standby=0xB0
	.EQU __sm_adc_noise_red=0x10
	.SET power_ctrl_reg=mcucr
	#endif
#endasm


//波特率9600/9个数据位/1个停止位/奇校验/收发开启/接收中断/地址过滤 
void usart_init(void) 
void usart_init(void) 
{   
  UCSRA=0x01; 
  UCSRB=0xDC; 
  UCSRC=0xB6; 
  UBRRH=0x00; 
  UBRRL=47;  
}
unsigned char crc8(unsigned char *ptr, unsigned char len)   
unsigned char crc8(unsigned char *ptr, unsigned char len)   
{  
  unsigned char i;  
  unsigned char crc=0;  
  while(len--!=0)   
   {  
     for(i=1; i!=0; i*=2)  
      {  
        if((crc&1)!=0) {crc/=2; crc^=0x8C;} 
        else crc/=2;  
        if((*ptr&i)!=0) crc^=0x8C;      
       }   
     ptr++;  
    }  
return(crc);  
}  


unsigned char  send[10                                        ];                               //发件箱 
unsigned char inbox[10                                        ];                               //收件箱 
unsigned char m=0,n=0;                                     //记忆中断次数  

//**************************************************************************************

interrupt[12] Rxd_isr(void)                                //接收中断 
{   
  if( UCSRA&28                          ){ n=UDR; n=0; UCSRA|=0x01                      ; } else      //接收出错就重新打开地址帧筛选功能 
  {
    if( UCSRB&2                            ) n=0;                               //检测到地址信息时计数清零
    inbox[n]=UDR;  n++;                                    //把接收到的数据保存到收件箱   
    if( inbox[0]==12                                         ) UCSRA&=254                       ; else UCSRA|=0x01                      ;  //地址筛选  
    if( n==10                                         )                                        //如果接收到完整的数据包
    { 
      n=0;
      if( inbox[10                                        -1]==crc8(inbox,10                                        -1) )          //如果crc8校验正确就... 
      {  
        send[0]=1;                                         //发件箱地址指向主机    
        //send[1]=?                                        //请更新发件箱的数据
        //send[n]=? 
        send[10                                        -1]=crc8(send,10                                        -1);                //产生发件箱的crc8校验码  
        PORTD.2=1                        ;                                        //使能MAX485准备发送 
        m=0;                                               //发送计数清零  
        UCSRB|=1                         ;                                       //第0个是地址数据
        UDR=send[m];                                       //发送第0个数据以便产生发送结束中断 
        
        OCR1A=inbox[3];                                    //收件箱测试(控制T/C1的PWM驱动LED)  
      }
    } 
  } 
} 

//**************************************************************************************

interrupt[14] Txd_Txcie_isr(void)                          //发送结束中断 
{ 
  m++;
  UCSRB&=254 ;                                             //数据帧
  if(m<10                                        ) UDR=send[m]; else PORTD.2=0                        ;
} 

//**************************************************************************************

void main(void) 
{ 
  usart_init();  
  PORTD.2=0                        ; 
  DDRD.2=1                         ;  
  TCCR1A   =0B10000001;                                    //OCR1A/PD5/8位快速PWM
  TCCR1B   =0B00001001;                                    //时钟1分频
  DDRD    |=0b00100000;                                    //输出使能
  OCR1A    =255;                                           //初始化PWM输出100%占空比     
  #asm("sei") 

  while (1) 
  { 
  
  }; 
}