I am trying to establish connection between two can board (ie. two cpu).I have written a
CAn transmit code. According to me i feel all initializations are done properly. All register
too reflect as i can see them using jtag emulator.My program wait for ACK so it get struck
there. But i want to monitor waveform on my tranmit pin of CAN AS per my code i have written
msg box data as high low so i can view then on DO.But i m unable to get any waveform.please
guide how to go further and also if i m wrong in my code correct me.
MY CPU is 2808

saurabh parmar
s...@yahoo.co.in

below mentiond is my code.
#include "Edutech_280X.h"
#include "lcd.h"
#include "Gpio.h"
// Prototype statements for functions found within this file.
void mailbox_check(int32 T1, int32 T2, int32 T3);
void mailbox_read(int16 i); 
extern void Edutech_Delay(long);

// Global variable for this example
struct ECAN_REGS ECanaShadow;

Uint32  ErrorCount;
Uint32  PassCount;
Uint32  MessageReceivedCount;
Uint32  TestMbox1 = 0;
Uint32  TestMbox2 = 0;
Uint32  TestMbox3 = 0;
Uint32 i;
void Init_CAN()
{
	// step 2  Set the CANTX and the CANRX pins to CAN functions:
		EALLOW;
	    ECanaShadow.CANMC.all = ECanaRegs.CANMC.all;
		ECanaShadow.CANMC.bit.SRES = 1; 
		ECanaRegs.CANMC.all = ECanaShadow.CANMC.all;
	    EDIS;
	
		EALLOW;
	    ECanaShadow.CANTIOC.all = ECanaRegs.CANTIOC.all;
	    ECanaShadow.CANTIOC.bit.TXFUNC = 1;
	    ECanaRegs.CANTIOC.all = ECanaShadow.CANTIOC.all;
		
	    ECanaShadow.CANRIOC.all = ECanaRegs.CANRIOC.all;
	    ECanaShadow.CANRIOC.bit.RXFUNC = 1;
	    ECanaRegs.CANRIOC.all = ECanaShadow.CANRIOC.all;
		EDIS;

	// extra

	// TAn, RMPn, GIFn bits are all zero upon reset and are cleared again
  // as a matter of precaution. 

		ECanaRegs.CANTA.all	= 0xFFFFFFFF;	/* Clear all TAn bits */      
		
		ECanaRegs.CANRMP.all = 0xFFFFFFFF;	/* Clear all RMPn bits */      

		EALLOW;
	    ECanaRegs.CANGIM.all=0x00000000;
		
		ECanaRegs.CANGIF0.all = 0xFFFFFFFF;	/* Clear all interrupt flag bits */ 
		ECanaRegs.CANGIF1.all = 0xFFFFFFFF;
		
	//ECanaRegs.CANTA.all = 0xFFFFFFFF;   // Clear all TAn    

	// step 3 After a reset, bit CCR (CANMC.12) and bit CCE (CANES.4) are set to 1.
	//This allows the user to configure the bit-timing configuration register
	//(CANBTC).If the CCE bit is set (CANES.4 = 1), proceed to next step; otherwise, set
	//the CCR bit (CANMC.12 = 1) and wait until CCE bit is set (CANES.4 = 1).

		EALLOW;
	    ECanaShadow.CANMC.all = ECanaRegs.CANMC.all;
	    ECanaShadow.CANMC.bit.CCR = 1; 	 
	    ECanaRegs.CANMC.all = ECanaShadow.CANMC.all;
	    EDIS;

    // Wait until the CPU has been granted permission to change the
    // configuration registers
    // Wait for CCE bit to be set..
			
	//	ECanaShadow.CANES.all = ECanaRegs.CANES.all;
		LcdDisplayStringCenter("1 loop starts",ROW1);
	   
	  	while(ECanaRegs.CANES.bit.CCE != 1 ){

//		   ECanaShadow.CANES.all = ECanaRegs.CANES.all;
    	} 
		LcdDisplayStringCenter("CCE is 1 now",ROW1);
    
	// Configure the eCAN timingProgram the CANBTC register with the appropriate timing values.
Make
	//sure that the values TSEG1 and TSEG2 are not 0. If they are 0, the module
	//does not leave the initialization mode.

    	EALLOW;
	    ECanaShadow.CANBTC.all = ECanaRegs.CANBTC.all;
		ECanaShadow.CANBTC.all = 0;
	    ECanaShadow.CANBTC.bit.BRPREG = 39;    // (BRPREG + 1) = 10 feeds a 15 MHz CAN clock
	    ECanaShadow.CANBTC.bit.TSEG2REG = 1;
	    ECanaShadow.CANBTC.bit.TSEG1REG =6; 
		ECanaShadow.CANBTC.bit.SAM = 1;
		ECanaRegs.CANBTC.all = ECanaShadow.CANBTC.all;
		EDIS;
		while(ECanaShadow.CANBTC.bit.TSEG2REG == 0)
		{	
				EALLOW;
				ECanaShadow.CANBTC.all = ECanaRegs.CANBTC.all;
				ECanaShadow.CANBTC.bit.TSEG2REG = 1;
				ECanaRegs.CANBTC.all = ECanaShadow.CANBTC.all;
				EDIS;
					    
		}

	   while(ECanaShadow.CANBTC.bit.TSEG1REG == 0)
	   {
				EALLOW;
				ECanaShadow.CANBTC.all = ECanaRegs.CANBTC.all;
				ECanaShadow.CANBTC.bit.TSEG1REG = 6;
				ECanaRegs.CANBTC.all = ECanaShadow.CANBTC.all;
				EDIS;

		}

	    EALLOW;
	    ECanaShadow.CANMC.all = ECanaRegs.CANMC.all;
	    ECanaShadow.CANMC.bit.CCR = 0;
        ECanaShadow.CANMC.bit.PDR = 0;
		ECanaShadow.CANMC.bit.WUBA = 0;
		ECanaShadow.CANMC.bit.CDR = 0;
		ECanaShadow.CANMC.bit.ABO = 0;
		ECanaShadow.CANMC.bit.STM = 0;
		ECanaShadow.CANMC.bit.SRES = 0;
		ECanaShadow.CANMC.bit.MBNR = 0;
	    ECanaRegs.CANMC.all = ECanaShadow.CANMC.all;
	    EDIS;

	//Initialize all bits of MSGCTRLn registers to zero.
		EALLOW;
		ECanaMboxes.MBOX0.MSGCTRL.all = 0x00000000;
		EDIS;

		ECanaShadow.CANES.all = ECanaRegs.CANES.all;

	     while(ECanaShadow.CANES.bit.CCE != 0 )
	    {
	      ECanaShadow.CANES.all = ECanaRegs.CANES.all;
	    }
		LcdDisplayStringCenter("init done..***",ROW1);
		
}

void main()
{

    Uint16  j;
    struct ECAN_REGS ECanaShadow;

 	MessageReceivedCount = 0;
    ErrorCount = 0;
    PassCount = 0;

	Edutech_Intdsp();
	DisableDog();
	GpioSelection(0x007E0000,PORTA);
	GpioPeripheral(0x50000000,PORTA,MUX2);
	Edutech_Delay(25);
	LcdInit();

	LcdDisplayStringCenter("1 check",ROW1);
	
	//  step 1 Enable clock to the CAN module.
	
	EALLOW;
	SysCtrlRegs.PCLKCR0.bit.ECANAENCLK = 1;
	EDIS;
	Init_CAN();	

	//1) Clear the appropriate bit in the CANTRS register to 0:
	
	ECanaRegs.CANTRR.bit.TRR0=1;
	while(ECanaRegs.CANTRS.bit.TRS0 !=0){};
	LcdDisplayStringCenter("3 loop",ROW1);
	//2) Disable the mailbox by clearing the corresponding bit in the mailbox
	//enable (CANME) register.

	ECanaRegs.CANME.bit.ME0 = 0;

	//	Load the message identifier (MSGID) register of the mailbox. 

	ECanaMboxes.MBOX0.MSGID.all = 0x05555555; 
//	ECanaMboxes.MBOX0.MSGID.all = 0x15AC0000; 
	
	EALLOW;
	ECanaMboxes.MBOX0.MSGCTRL.all = 0;
	ECanaMboxes.MBOX0.MSGCTRL.bit.DLC = 8;
	ECanaMboxes.MBOX0.MSGCTRL.bit.RTR = 0;      
	EDIS;

	//Set the mailbox direction by clearing the corresponding bit in the CANMD
	//register.
	
	ECanaRegs.CANMD.bit.MD0 = 0; 
	
	//Set the mailbox enable by setting the corresponding bit in the CANME
	//register
	
	ECanaRegs.CANME.bit.ME0 = 1;

	// 1) Write the message data into the mailbox data field.
	
	ECanaMboxes.MBOX0.MDL.all = 0x05555555;
    ECanaMboxes.MBOX0.MDH.all = 0x05555555;

	//Set the corresponding flag in the transmit request register
	//(CANTRS.1 = 1) to start the transmission of the message. The CAN
	//module now handles the complete transmission of the CAN message.
	//ECanaRegs.CANTRR.bit.TRR0=1;
	i=0;
	for(;;)                                
    {
 			 
	  i++;
      LcdDisplayStringCenter("tx srt",ROW1);
       ECanaRegs.CANTRS.bit.TRS0 = 1;

     	// Set TRS for all transmit mailboxes
    	//Wait until the transmit-acknowledge flag of the corresponding mailbox is
		//set (TA.1 = 1). After a successful transmission, this flag is set by the CAN
		//module.
       while(ECanaRegs.CANTA.bit.TA0 != 1 ){} // Wait for all TAn bits to be set..
	   LcdDisplayStringCenter("tx compl",ROW1);
		
       ECanaRegs.CANTA.bit.TA0= 1;

    }
 
}

//===========================================================================
// No more.
//===========================================================================

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