CCS/TMS320F28069M: CAN module not receiving data in SCC mode or eCAN mode.

Part Number: TMS320F28069M

Tool/software: Code Composer Studio

Hello,

I have been trying to receive data through can communiaction in f28069. The sender is a CAN module for Raspberry pi based on MC2515 transmitting 500kbps with 75% sample point. f28069 can transmit data without issues to the Raspberry pi. 

following is initialization code:

void can_init_scc_recv_mode(void)
{
    /* 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 or return
     false data. */

    struct ECAN_REGS ECanaShadow;

        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 = 0;
        ECanaRegs.CANMC.all = ECanaShadow.CANMC.all;

       /* 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=0x00040053;   //500kbps 75% sample point
        ECanaRegs.CANBTC.all = ECanaShadow.CANBTC.all;

        /* The previous block is for 80 MHz SYSCLKOUT. (40 MHz CAN module clock Bit rate = 0.5 Mbps
           See Note at end of file. */

        /*CAN GAM settings allowed only in initialization mode*/
        ECanaShadow.CANGAM.all=0x8FFFFFFF;
        ECanaShadow.CANGAM.bit.AMI=1;
        ECanaRegs.CANGAM.all= ECanaShadow.CANGAM.all;
        /**********************************************/

        ECanaShadow.CANMC.all = ECanaRegs.CANMC.all;
        ECanaShadow.CANMC.bit.CCR = 0 ;            /*Set CCR = 0*/
        ECanaRegs.CANMC.all = ECanaShadow.CANMC.all;

        /*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;
}

For configuring mailboxes i have seperate code:

void InitCANMailbox(uint16_t mailboxIndex, uint32_t filterMaskID,
                      uint16_t mailboxDirection, uint16_t mailBoxDLC)
{
    Uint32 mask;
    Uint32 CAN_MD_REG;
    Uint32 CAN_ME_REG;

    ECanaMboxes.MBOX[mailboxIndex].MSGID.all = filterMaskID;
    ECanaMboxes.MBOX[mailboxIndex].MSGCTRL.bit.DLC = mailBoxDLC;

    mask = 0u;
    mask = (Uint32)(0x00000001u) << mailboxIndex;

    CAN_MD_REG = ECanaRegs.CANMD.all;
    CAN_MD_REG &= ~(mask);   /*first clear the corresponding bit to modify it*/
    /*after the bit is cleared then modify it 0=out 1=in */
    CAN_MD_REG |= ((uint32_t)mailboxDirection << (uint32_t)mailboxIndex);
    ECanaRegs.CANMD.all = CAN_MD_REG;

    CAN_ME_REG = ECanaRegs.CANME.all;
    CAN_ME_REG |= mask;
    ECanaRegs.CANME.all = CAN_ME_REG;    /*enable = 1*/
}

And finally in main i also change the AME bit for each mailbox in following manner:

    ECanaMboxes.MBOX[0].MSGID.bit.AME=1; //repeat for mailboxes 0-15

Change Local Acceptance mask for LAM0 and LAM3 as following:

    ECanaLAMRegs.LAM0.all=0x8FFFFFFF;
    ECanaLAMRegs.LAM3.all=0x8FFFFFFF;
    ECanaLAMRegs.LAM0.bit.LAMI=1;
    ECanaLAMRegs.LAM3.bit.LAMI=1;

I Have tried the same in eCAN mode by changing the SCB bit to 1 but it didnt help i still cant receive data.

I have changed mailbox definitions in ECAN.h to the following:

struct ECAN_MBOXES {
    struct MBOX MBOX[32];
};

I can only receive can messages of message ID with all bits '0'. I cannot receive any message with any other msg id apart from 0. I can receive this message in mailbox 15 because it has the highest receive priority and any other message is not receievd.

Thanks,

Shadab