基于SJA1000的CAN总线测试程序

**************************
*函数功能：设置SJA1000的时钟分频器
*入口参数：无
*出口参数：setting_success
****************************************************************/
bit Setting_SJA1000_CDR(void)
{
bit setting_success;

while(Setting_SJA1000_resetmode()==0)
{
Setting_SJA1000_resetmode(); //设置SJA工作在复位模式
}

Write_SJA1000(REG_CDR,SJA_CDR);

if(Read_SJA1000(REG_CDR)==SJA_CDR)
{
setting_success=1; //滤波器设置成功
}
else
{
setting_success=0; //滤波器设置失败
}

return(setting_success);
}

/****************************************************************
*函数功能：设置SJA1000的输出控制寄存器
*入口参数：无
*出口参数：setting_success
****************************************************************/
bit Setting_SJA1000_OCR(void)
{
bit setting_success;

while(Setting_SJA1000_resetmode()==0)
{
Setting_SJA1000_resetmode(); //设置SJA工作在复位模式
}

Write_SJA1000(REG_OCR,SJA_OCR);

if(Read_SJA1000(REG_OCR)==SJA_OCR)
{
setting_success=1; //滤波器设置成功
}
else
{
setting_success=0; //滤波器设置失败
}

return(setting_success);
}

/****************************************************************
*函数功能：初始化SJA1000
*入口参数：无
*出口参数：setting_success
****************************************************************/
void Initial_SJA1000(void)
{
while(Judge_SJA1000_connect==0);

do
{
Setting_SJA1000_resetmode();
}
while(Setting_SJA1000_resetmode()==0);

while(Setting_SJA1000_CDR()==0);
while(Setting_SJA1000_rate()==0);
while(Setting_SJA1000_OCR()==0);
while(Setting_SJA1000_dataselect()==0)

do
{
Setting_SJA1000_workingmode();
}
while(Setting_SJA1000_workingmode()==0);

}

/****************************************************************
*函数功能：初始化发送数据
*入口参数：无
*出口参数：setting_success，指示初始化是否成功
****************************************************************/
bit Initial_transmitter_BUF(void)
{
bit setting_success=0;

send_BUF.IDH8=0x30;
send_BUF.IDL_R_DLC=0x22; //IDL_R_DLC。4即为RTR位，数据=0，远程=1；
send_BUF.Frame_Data[0]=0x10;
send_BUF.Frame_Data[1]=0x00;

setting_success = 1;

return(setting_success);
}

/****************************************************************
*函数功能：对SJA1000发送数据
*入口参数：无
*出口参数：无
****************************************************************/
void Transmitter_SJA1000(void)
{
unsigned char state;
unsigned char i;

do
{
Setting_SJA1000_workingmode();
}
while(Setting_SJA1000_workingmode()==0);

while(Initial_transmitter_BUF()==0); //初始化发送数据

do
{
state = Read_SJA1000(REG_STATUS);//REG_STATUS为SJA1000的状态寄存器
}
//查询SJA1000是否处于接收状态，发送完毕状态，或者发送缓存器被锁；
while( ((state&0x10)==0x10) & ((state&0x08)!=0x08) & ((state&0x04)!=0x04) );

Write_SJA1000(REG_TxBuffer1,send_BUF.IDH8);
Write_SJA1000(REG_TxBuffer2,send_BUF.IDL_R_DLC);
for(i=0;i<2;i++)
{
Write_SJA1000(REG_TxBuffer3+i,send_BUF.Frame_Data[i]);
}

Write_SJA1000(REG_COMMAND,TR_CMD);

do
{
state = Read_SJA1000(REG_STATUS);//REG_STATUS为SJA1000的状态寄存器
}
while( (state&0x08)!=0x08);//查询SJA1000是否发送完毕状态
}

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

void main(void)
{
unsigned char i;
Initial_SJA1000();
delay1ms(1);

while(1)
{
if((P1_0==0)|(P1_1==0)|(P1_2==0))
{
delay1ms(5);

if((P1_0==0)|(P1_1==0)|(P1_2==0))
{
while((P1_0==0)|(P1_1==0)|(P1_2==0));
for(i=0;i<100;i++)
{
Transmitter_SJA1000();
}
}
}
}
}