基于AT91RM9200的CAN通讯程序

#include "sja1000.h"
unsigned int T_flag0=0;
unsigned int T_flag1=0;

//unsigned char data[11] = {'\0'};
//unsigned char Rx_Buf0[11] = {'\0'};
unsigned char Tx_Buf0[9] = {'\0'};
unsigned char Tx_Buf1[9] = {'\0'};
//unsigned char Rx_Buf1[11] = {'\0'};

/*writ to the register with tht data
 chanal--通道号，可选CAN总线1，CAN总线2
 reg-----寄存器号
 data----寄存器数据*/
void setcanport(unsigned char chanal, unsigned int reg, unsigned char data1)
{
    if(!chanal)
 BASEADD = 0x50000000;
    else
 BASEADD = 0x60000000;
 
 printf("\nThe %d will be writed to register %d\n ",data1,reg);
    __asm
    {
 STRB reg,[BASEADD,#4]
 STRB data1,[BASEADD]
    }
}

/*read the data of the register to the return
 chanal--通道号，可选CAN总线1，CAN总线2
 reg-----寄存器号
 返回值--寄存器数据*/
unsigned char getcanport(unsigned char chanal, unsigned char reg)
{
    unsigned char temp;
    if(!chanal)
 BASEADD = 0x50000000;
    else
 BASEADD = 0x60000000;
  
    __asm    
    {
 STRB reg,[BASEADD,#4]
 LDRB temp,[BASEADD]
 }
 return (temp);
}

/*Receive one message
 chanal--通道号，可选CAN总线1，CAN总线2
 返回值--数据个数*/
unsigned char getdata(unsigned char chanal, unsigned char *buf)
{ 
 int num,i;
 unsigned char data[11] = {'\0'};
 if(!chanal)
 BASEADD = 50000000;
    else
 BASEADD = 60000000;
 
 do 
 {
 }while((getcanport(chanal,StatusReg) & RBS_Bit) != RBS_Bit);
 
 data[0] = getcanport(chanal,RxBuffer1);
 data[1] = getcanport(chanal,RxBuffer2);
 data[2] = getcanport(chanal,RxBuffer3);
 data[3] = getcanport(chanal,RxBuffer4);
 data[4] = getcanport(chanal,RxBuffer5);
 data[5] = getcanport(chanal,RxBuffer6);
 data[6] = getcanport(chanal,RxBuffer7);
 data[7] = getcanport(chanal,RxBuffer8);
 data[8] = getcanport(chanal,RxBuffer9);
 data[9] = getcanport(chanal,RxBuffer10);
 
 num = data[1]&0x0f;

 
 for(i=0;i  {
 *(buf++)=data[i+2];
 }

 setcanport(chanal,CommandReg,RRB_Bit);

 *buf=0;

 return (num);

 
}

/*Transmit one message
 num-----数据个数
 data----数据
 返回值--0 忙*/
unsigned char senddata(unsigned char chanal, unsigned char *buf)
{     
 
 unsigned char temp = 0;
 unsigned char data[11] = {'\0'};
 int i;
 
 if(!chanal)
  BASEADD = 0x50000000;
 else
  BASEADD = 0x60000000;
 //temp = getcanport(chanal, StatusReg);

 if((getcanport(chanal,StatusReg) & TBS_Bit) == TBS_Bit)
 {
  for(i=0;i<8;i++)
  {
  data[i]=*(buf+i);
  }
  temp = getcanport(chanal, StatusReg);
  setcanport(chanal,TxBuffer1,0x00);
  setcanport(chanal,TxBuffer2,0x08);
  setcanport(chanal,TxBuffer3,data[0]);
  setcanport(chanal,TxBuffer4,data[1]);
  setcanport(chanal,TxBuffer5,data[2]);
  setcanport(chanal,TxBuffer6,data[3]);
  setcanport(chanal,TxBuffer7,data[4]);
  setcanport(chanal,TxBuffer8,data[5]);
  setcanport(chanal,TxBuffer9,data[6]);
  setcanport(chanal,TxBuffer10,data[7]);
  
  setcanport(chanal,CommandReg,0x01);
  
  do 
    {
       temp = getcanport(chanal, StatusReg);
       if ((temp & TCS_Bit)==TCS_Bit)
          break;
    } while(1);     //If it is transmitted succeded?

  return (1);
 }
 else if(!chanal)
 {
  if(!T_flag0)
  {
   for(i=0;i<8;i++)
   {
   Tx_Buf0[i]=*(buf+i);
   }
   T_flag0=1;//传输标志，1表示一个报文等待发送
  }
  else return (0);
 }
 else
 {
  if(!T_flag1)
  {
   for(i=0;i<8;i++)
   {
   Tx_Buf1[i]=*(buf+i);
   }
   T_flag1=1;//传输标志，1表示一个报文等待发送
  }
  else return (0);
 }
 
}

/*Initial the SJA1000 It just is BasicCAN */
void init_sja1000(unsigned char chanal)
{
 
 unsigned char temp = 0;
//?SJA中断禁止

//外部中断禁止
 if(!chanal)//禁止can0中断
 {
  __asm
  {
  str 0x00000000,[0xfffff120]
  }
  __asm
  {
  str 0x00000000,[0xfffff124]
  }
 } 
 else//禁止can1中断
 {
  __asm
  {
  str 0x00000000,[0xfffff120]
  }
  __asm
  {
  str 0x00000000,[0xfffff124]
  }
 }

//进入复位请求设置模式
 while((temp&RM_RR_Bit)!=RM_RR_Bit)
 {
 printf("\n0x01 will be set to ModeControlReg\n");
 setcanport(chanal, ModeControlReg,0x07);/*Config MOD&CR register，初始化INT*/
 
 temp = getcanport(chanal, ModeControlReg);
 printf("\nModeControlReg=%d\n",temp);
 
 }
//设置接收码
 setcanport(chanal, AcceptCodeReg, 0x01);
 temp = getcanport(chanal, AcceptCodeReg);
//设置屏蔽码
 setcanport(chanal, AcceptMaskReg, 0xff);
 temp = getcanport(chanal, AcceptMaskReg);
//设置总线bps
 setcanport(chanal, BusTiming0Reg, 0x47);
 temp = getcanport(chanal, BusTiming0Reg);//400kbps
 setcanport(chanal, BusTiming1Reg, 0xaf);
 temp = getcanport(chanal, BusTiming1Reg);
//设置CAN输出模式 
 setcanport(chanal, OutControlReg, 0xda);
 temp = getcanport(chanal,OutControlReg);
//设置时钟分频寄存器
 setcanport(chanal, ClockDivideReg, 0x48);
 temp = getcanport(chanal, ClockDivideReg);

/*清除复位模式位*/
 do
 {
 setcanport(chanal, ModeControlReg, 0X06);/*Config MOD&CR register*/
 temp = getcanport(chanal, ModeControlReg);
 }while(((getcanport(chanal, ModeControlReg)) & RM_RR_Bit)!=ClrByte);

//外部中断使能
 if(!chanal)//禁止can0中断
 {
  __asm
  {
  str 0x00000000,[0xfffff120]
  }
  __asm
  {
  str 0x00000000,[0xfffff124]
  }
 } 
 else//禁止can1中断
 {
  __asm
  {
  str 0x00000000,[0xfffff120]
  }
  __asm
  {
  str 0x00000000,[0xfffff124]
  }
 }

//?SJA中断使能

}

int main()
{
 unsigned char *buf;
 int i;
 unsigned char d[5][9]={"bbbbbbbb;","12345678","90123456","78787878","abcdefgh"};

 unsigned long t;
//    init irq1 an irq2 for sja1000 u2 u3

//nIRQ AIC_IECR&AIC_IDCR ENABLE INIT
 __asm
 {
 str 0x00000000,[0xfffff120]
 }
 __asm
 {
 str 0x00000000,[0xfffff124]
 }

//nIRQ AIC_SMR,&AIC_SVR config int
 __asm
 {
 ldr t,[0xfffff004]
 }
 __asm
 {
 orr t,t,#0x03//priority level3,Level Sensitive(interal) Low-level Sensitive(external)
 str t,[0xfffff004]
 }
 __asm
 {
 ldr t,[0xfffff008]
 }
 __asm
 {
 orr t,t,#0x03//priority level3,Level Sensitive(interal) Low-level Sensitive(external)
 str t,[0xfffff008]
 }
//配置AIC_SVR
 __asm
 {
 str t,[0xfffff084]
 }
 __asm
 {
 str t,[0xfffff088]
 }

 
 init_sja1000(0);

//
 for(i=0;i<5;i++)
 {
 buf=&d[i][0];
 senddata(0,buf);
 };
 
 while(1){
 
 getdata(0,buf);

 };
 
}

说明：

系统是测试CAN0接口和CAN卡的通信程序

波特率设置为：
   BAR0=0x47=71;
   BAR1=0xaf=175;

接口为:
   9200的CAN口：3脚为CANL，4脚为CANH
   对应CAN卡：  2脚为CANL，4脚为CANH