can.h

51系列单片机CAN多点通信C语言源代码

#ifndef __CAN__
#define __CAN__

/////////CAN 消息初始化程序////////////////
//////can.h//////////////////

	
#include "canreg.h"

typedef unsigned char uchar;
typedef unsigned int uint;
typedef unsigned long ulong;


void init_msg_object_TX (char MsgNum,int id)//初始化发送消息体
{ int temp;
  SFRPAGE = CAN0_PAGE;
  CAN0ADR = IF1CMDMSK;  // Point to Command Mask 1
  CAN0DAT = 0x00b3;     // Set to WRITE, & alter all Msg Obj except ID MASK bits
  CAN0ADR = IF1ARB1;    // Point to arbitration1 register
  CAN0DAT = 0x0000;     // Set arbitration1 ID to highest priority
  //CAN0DAT = 0xA008;     // Autoincrement to Arb2 high byte:发送标识符设置
   temp=id<<2;
   temp&=0x1fff;
   temp|=0xa000;
   CAN0DAT=temp;

  CAN0DAT = 0x0087;     // Msg Cntrl: DLC = 7, remote frame function not enabled，数据字节大小设置
  CAN0ADR = IF1CMDRQST; // Point to Command Request reg.
  CAN0DAT = MsgNum;     // Select Msg Obj passed into function parameter list
                        // --initiates write to Msg Obj
  // 3-6 CAN clock cycles to move IF reg contents to the Msg Obj in CAN RAM.
}


void init_msg_object_RX (char MsgNum,int id)
{ 
  int temp;
  int temp1;
  SFRPAGE  = CAN0_PAGE;
  CAN0ADR  = IF2CMDMSK;  // Point to Command Mask 1
  CAN0DAT  = 0x00fb;     // 必须用f8
                         // and data bits
  CAN0ADR  = IF2MSK1;
  CAN0DAT  = 0x0000;     //MSK15~0标识符

 // CAN0ADR  = IF2MSK2;
  temp=id<<2;
  temp&=0x1fff; 

  temp1=temp;             
  temp1|=0xc000;
  CAN0DAT =temp1;
     
  CAN0ADR  = IF2ARB1;    // Point to arbitration1 register
  CAN0DAT  = 0x0000;     // Set arbitration1 ID to "0"
  //CAN0DAT  = 0x8000;     // Arb2 high byte:Set MsgVal bit, no extended ID,

  temp|=0x8000;
  CAN0DAT =temp;

  CAN0DAT  = 0x1487;     // Msg Cntrl: set RXIE, remote frame function disabled
  CAN0ADR  = IF2CMDRQST; // Point to Command Request reg.
  CAN0DATL = MsgNum;     // Select Msg Obj passed into function parameter list
                         // --initiates write to Msg Obj
  // 3-6 CAN clock cycles to move IF register contents to the Msg Obj in CAN RAM
}


void clear_msg_objects (void) //将所有消息清零
{	
	uchar i;
   	SFRPAGE = CAN0_PAGE;
	CAN0ADR = IF1CMDMSK;       
	CAN0DATL = 0xFF;            
	for (i=1;i<33;i++)
      {
		CAN0ADR = IF1CMDRQST;     
		CAN0DATL = i;
      }   
}


void start_CAN (void)
{
  SFRPAGE  = CAN0_PAGE;
  CAN0CN  |= 0x41;       // Configuration Change Enable CCE and INIT
  CAN0ADR  = BITREG   ;  // Point to Bit Timing register
  CAN0DAT  = 0x2640;     // see above

  CAN0ADR  = IF1CMDMSK;  // Point to Command Mask 1
  CAN0DAT  = 0x0087;     // 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
}




#endif