有关C8051F040单片机CAN总线配置问题
请教高手指点一下，C8051F040单片机配置CAN总线各个寄存器的顺序，以及如何配置这些寄存器。请详细点。书上有配置好的程序，但我不明白为什么这样配，每个寄存器都到底干什么的 这是我刚开始时用的程序，只是在例程上修改了点，注释有中文有英文，别告诉我你看不懂英文哦！void clear_msg_objects (void)
{
uchar i;
SFRPAGE= CAN0_PAGE;
CAN0ADR= IF1CMDMSK; // Point to Command Mask Register 1
CAN0DATL = 0xFF; // Set direction to WRITE all IF registers to Msg Obj
for (i=1;i<33;i++)
{
CAN0ADR = IF1CMDRQST; // Write blank (reset) IF registers to each msg obj
CAN0DATL = i;
}
}
void init_msg_object_TX (uchar MsgNum,uint id)
{
uint tempreg;
SFRPAGE = CAN0_PAGE;
CAN0ADR = IF1CMDMSK; //指向IF1 Command Mask Registers
CAN0DAT = 0x00f3;
/* IF1 Command Mask Registers=0x00b3
WR/RD=1,Mask=0,Arb=1,Control=1,ClrIntPnd=0,TxRqst=0,DataA=1,DataB=1,一次发送8字节数据*/
tempreg=0x0000;
// CAN0ADR = IF1MSK1;
// CAN0DAT = 0x0000;
CAN0ADR = IF1MSK2;//test
CAN0DAT = tempreg; //test2fc0
CAN0ADR = IF1ARB1;
CAN0DAT = 0x0000;
/*IF1 Arbitration Registers1 =0x0000，即ID15-0=0*/
CAN0ADR = IF1MSGC;
CAN0DAT = 0x0084; //发送4个字节数据
/*IF1 Message Control Registers=0x0088
NewDat=0,MsgLst=0,IntPnd=0,UMask=0,TxIE=0,RxIE=0,RmtEn=0,TxRqst=0
EoB=1,DLC3-0=0100,即数据长度为4*/
tempreg=id<<2;//标准id为ID28-ID18,所以要左移2位
tempreg&=0x1fff;
tempreg|=0xa000;
CAN0ADR = IF1ARB2;
CAN0DAT = tempreg; //地址自增，指向IF1 Arbitration Registers2
/*IF1 Arbitration Registers2=101(id)00b
MsgVal=1,Xtd=0,为标准模式，扩展ID无效，Dir=1，为发送*/
CAN0ADR = IF1CMDRQST;
CAN0DAT = MsgNum;
/*IF1 Command Request Registers=MsgNum,将以上配置写入MsgNum号消息*/
}
void init_msg_object_RX (uchar MsgNum,uint id)
{
uint tempreg;
SFRPAGE = CAN0_PAGE;
CAN0ADR = IF2CMDMSK;
CAN0DAT = 0x00fb;
/* IF2 Command Mask Registers=0x00bb
WR/RD=1,Mask=0,Arb=1,Control=1,ClrIntPnd=1,TxRqst=0,DataA=1,DataB=1,一次发送8字节数据*/
tempreg=0x0000;
// CAN0ADR = IF2MSK1;
// CAN0DAT = 0x0000;
CAN0ADR = IF2MSK2;//test
CAN0DAT = tempreg; //test2fc0
CAN0ADR = IF2ARB1;
CAN0DAT = 0x0000;
/*IF2 Arbitration Registers1 =0x0000，即ID15-0=0*/
CAN0ADR = IF2MSGC;
CAN0DAT = 0x1488;
/*IF2 Message Control Registers=0x0488
NewDat=0,MsgLst=0,IntPnd=0,UMask=1,TxIE=0,RxIE=1,接收中断使能;RmtEn=0,TxRqst=0
EoB=1,DLC3-0=1000,即数据长度为8*/
tempreg=(id<<2);//标准id为ID28-ID18,所以要左移2位
tempreg&=0x1fff;
tempreg|=0x8000;
CAN0ADR = IF2ARB2;
CAN0DAT = tempreg;
/*IF2 Arbitration Registers2=100(id)00b
MsgVal=1,Xtd=0,为标准模式，扩展ID无效，Dir=0，为接收*/
CAN0ADR = IF2CMDRQST;
CAN0DATL = MsgNum;
/*IF2 Command Request Registers=MsgNum,将以上配置写入MsgNum号消息*/
}
//Start CAN
void start_CAN (void)
{
SFRPAGE= CAN0_PAGE;
CAN0CN|= 0x41; // 进入初始化状态，置位 CCE & INIT
CAN0ADR= BITREG ;// 将索引指向 Timing register
CAN0DAT= 0x4FC1; // 由上面计算得来
//CAN0DAT= 0x5EC0;//250MHz
//CAN0DAT= 0x4FC3; //250k
CAN0ADR= IF1CMDMSK;// 将索引指向Command Mask 1
CAN0DAT= 0x0083; // Config for TX : WRITE to CAN RAM, write data bytes,
// set TXrqst/NewDat, clr IntPnd
// RX-IF2 operation may interrupt TX-IF1 operation
CAN0ADR= IF2CMDMSK;// Point to Command Mask 2
CAN0DATL = 0x1F; // Config for RX : READ CAN RAM, read data bytes,
// clr NewDat and IntPnd
CAN0CN|= 0x06; // Global Int. Enable IE and SIE
CAN0CN&= ~0x41; // Clear CCE and INIT bits, starts CAN state machine
} 谢谢给的程序，对我还是有所启发的，谢谢！ mark mark mark 有用，mark mark mark，学习中... mark!!!!学习学习！
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