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CCS/TMS320F28069: Ecan CCE bits never get cleared

Part Number: TMS320F28069

Tool/software: Code Composer Studio

ECanaShadow.CANES.bit.CCE != 0 // never gets cleared, I am trying to use example of RXLOOP given in spra876b(http://www.ti.com/lit/zip/spra876)

// Included Files
//
#include "DSP28x_Project.h"     // Device Headerfile and Examples Include File
#include "F2806x_Ecan.h"
long      RXCOUNT = 0;
long	  i;
volatile struct ECAN_REGS ECanaRegs;
volatile  struct ECAN_MBOXES ECanaMboxes;
void MBXwrA(void);                 // This function initializes all 32 MBOXes of CAN-A
void mailbox_read(int16 i);

Uint32  TestMbox1 = 0;
Uint32  TestMbox2 = 0;
Uint32  TestMbox3 = 0;
main()
{

/* Create a shadow register structure for the CAN control registers. This is
 needed, since, only 32-bit access is allowed to these registers. 16-bit access
 to these registers could potentially corrupt the register contents. This is
 especially true while writing to a bit (or group of bits) among bits 16 - 31 */

struct ECAN_REGS ECanaShadow;
struct ECAN_MBOXES ECanaMboxes;

// Step 1. Initialize System Control:
// PLL, WatchDog, enable Peripheral Clocks
// This example function is found in the DSP280x_SysCtrl.c file.
   InitSysCtrl();

/* Initialize the CAN module */

   InitECanGpio();
   InitECan();


	EALLOW;

/* Zero out (or initialize) the entire MBX RAM area */

//   MBXwrA();
//	MBXwrB();

/* Write to the MSGID field 0f CAN-A - MBX number is written as its MSGID */
	ECanaMboxes.MBOX25.MSGID.all = 0x001;
    ECanaMboxes.MBOX25.MSGCTRL.bit.DLC = 8;
    ECanaMboxes.MBOX25.MDL.all = 0;
    ECanaMboxes.MBOX25.MDH.all = 0;



/* Configure CAN-A Mailboxes as Receive mailboxes */

	ECanaShadow.CANMD.all = ECanaRegs.CANMD.all;
	ECanaShadow.CANMD.all = 0xFFFFFFFF;
	ECanaRegs.CANMD.all = ECanaShadow.CANMD.all;



/* Enable Mailboxes */

	ECanaShadow.CANME.all = ECanaRegs.CANME.all;
	ECanaShadow.CANME.all = 0xFFFFFFFF;
	ECanaRegs.CANME.all = ECanaShadow.CANME.all;
	


/* Begin receiving */

    while(1)
    {
     int j;
     while(ECanaRegs.CANRMP.all != 0xFFFFFFFF) {}  // Wait for all RMPn to be set..
     ECanaRegs.CANRMP.all = 0xFFFFFFFF;			   // Clear all RMPn bits and start
     RXCOUNT++ ;		                           // all over again...
     //Read from Receive mailboxes and begin checking for data */
           for(j=16; j<32; j++)         // Read & check 16 mailboxes
              mailbox_read(j);         // This func reads the indicated mailbox data
           if(RXCOUNT==1000){break;}
    }
ESTOP0;
}


/* Zero-out the MBX RAM of CAN-A */

void MBXwrA()
    {
    int j;
    volatile struct MBOX *Mailbox  = (void *) 0x6100;

        for(j=0; j<32; j++)
        {
            Mailbox->MSGID.all = 0;
            Mailbox->MSGCTRL.all = 0;
            Mailbox->MDH.all = 0;
            Mailbox->MDL.all = 0;
            Mailbox = Mailbox + 1;

        }
    }

void mailbox_read(int16 MBXnbr)
{
   volatile struct MBOX *Mailbox;
   Mailbox = &ECanaMboxes.MBOX0 + MBXnbr;
   TestMbox1 = Mailbox->MDL.all; // = 0x9555AAAn (n is the MBX number)
   TestMbox2 = Mailbox->MDH.all; // = 0x89ABCDEF (a constant)
   TestMbox3 = Mailbox->MSGID.all;// = 0x9555AAAn (n is the MBX number)

} // MSGID of a rcv MBX is transmitted as the MDL data.





// CAN initialization is as follows:
 volatile  struct ECAN_REGS ECanaShadow;
 volatile struct  ECAN_REGS ECanaRegs;
 volatile  struct ECAN_MBOXES ECanaMboxes;
   EALLOW;     // EALLOW enables access to protected bits

/* Configure eCAN RX and TX pins for CAN operation using eCAN regs*/

    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;

/* Configure eCAN for HECC mode - (reqd to access mailboxes 16 thru 31) */
                                    // HECC mode also enables time-stamping feature

    ECanaShadow.CANMC.all = ECanaRegs.CANMC.all;
    ECanaShadow.CANMC.bit.SCB = 1;
    ECanaRegs.CANMC.all = ECanaShadow.CANMC.all;


/* Initialize all bits of 'Message Control Register' to zero */
// Some bits of MSGCTRL register come up in an unknown state. For proper operation,
// all bits (including reserved bits) of MSGCTRL must be initialized to zero

    ECanaMboxes.MBOX0.MSGCTRL.all = 0x00000000;
    ECanaMboxes.MBOX1.MSGCTRL.all = 0x00000000;
    ECanaMboxes.MBOX2.MSGCTRL.all = 0x00000000;
    ECanaMboxes.MBOX3.MSGCTRL.all = 0x00000000;
    ECanaMboxes.MBOX4.MSGCTRL.all = 0x00000000;
    ECanaMboxes.MBOX5.MSGCTRL.all = 0x00000000;
    ECanaMboxes.MBOX6.MSGCTRL.all = 0x00000000;
    ECanaMboxes.MBOX7.MSGCTRL.all = 0x00000000;
    ECanaMboxes.MBOX8.MSGCTRL.all = 0x00000000;
    ECanaMboxes.MBOX9.MSGCTRL.all = 0x00000000;
    ECanaMboxes.MBOX10.MSGCTRL.all = 0x00000000;
    ECanaMboxes.MBOX11.MSGCTRL.all = 0x00000000;
    ECanaMboxes.MBOX12.MSGCTRL.all = 0x00000000;
    ECanaMboxes.MBOX13.MSGCTRL.all = 0x00000000;
    ECanaMboxes.MBOX14.MSGCTRL.all = 0x00000000;
    ECanaMboxes.MBOX15.MSGCTRL.all = 0x00000000;
    ECanaMboxes.MBOX16.MSGCTRL.all = 0x00000000;
    ECanaMboxes.MBOX17.MSGCTRL.all = 0x00000000;
    ECanaMboxes.MBOX18.MSGCTRL.all = 0x00000000;
    ECanaMboxes.MBOX19.MSGCTRL.all = 0x00000000;
    ECanaMboxes.MBOX20.MSGCTRL.all = 0x00000000;
    ECanaMboxes.MBOX21.MSGCTRL.all = 0x00000000;
    ECanaMboxes.MBOX22.MSGCTRL.all = 0x00000000;
    ECanaMboxes.MBOX23.MSGCTRL.all = 0x00000000;
    ECanaMboxes.MBOX24.MSGCTRL.all = 0x00000000;
    ECanaMboxes.MBOX25.MSGCTRL.all = 0x00000000;
    ECanaMboxes.MBOX26.MSGCTRL.all = 0x00000000;
    ECanaMboxes.MBOX27.MSGCTRL.all = 0x00000000;
    ECanaMboxes.MBOX28.MSGCTRL.all = 0x00000000;
    ECanaMboxes.MBOX29.MSGCTRL.all = 0x00000000;
    ECanaMboxes.MBOX30.MSGCTRL.all = 0x00000000;
    ECanaMboxes.MBOX31.MSGCTRL.all = 0x00000000;

// 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 */

    ECanaRegs.CANGIF0.all = 0xFFFFFFFF; /* Clear all interrupt flag bits */
    ECanaRegs.CANGIF1.all = 0xFFFFFFFF;

/* Configure bit timing parameters for eCANA*/

    ECanaShadow.CANMC.all = ECanaRegs.CANMC.all;
    ECanaShadow.CANMC.bit.CCR = 1 ;            // Set CCR = 1
    ECanaRegs.CANMC.all = ECanaShadow.CANMC.all;

    // Wait until the CPU has been granted permission to change the configuration registers
    do
    {
      ECanaShadow.CANES.all = ECanaRegs.CANES.all;
    } while(ECanaShadow.CANES.bit.CCE != 1 );       // Wait for CCE bit to be set..

    ECanaShadow.CANBTC.all = 0;
    /* The following block is for 80 MHz SYSCLKOUT. (40 MHz CAN module clock Bit rate = 1 Mbps
       See Note at end of file. */

    ECanaShadow.CANBTC.bit.BRPREG = 1;
    ECanaShadow.CANBTC.bit.TSEG2REG = 2;//4
    ECanaShadow.CANBTC.bit.TSEG1REG = 10;//13

    ECanaShadow.CANBTC.bit.SAM = 1;
    ECanaRegs.CANBTC.all = ECanaShadow.CANBTC.all;

    ECanaShadow.CANMC.all = ECanaRegs.CANMC.all;
    ECanaShadow.CANMC.bit.CCR = 0 ;            // Set CCR = 0
    ECanaRegs.CANMC.all = ECanaShadow.CANMC.all;
    //ECanaShadow.CANES.bit.CCE = 1;
    // Wait until the CPU no longer has permission to change the configuration registers
   do
    {
      ECanaShadow.CANES.all = ECanaRegs.CANES.all;
    } while(ECanaShadow.CANES.bit.CCE != 0);       // Wait for CCE bit to be  cleared..

/* Disable all Mailboxes  */
    ECanaRegs.CANME.all = 0;        // Required before writing the MSGIDs

    EDIS;
}
#endif // endif DSP28_ECANA