TMS320F28388D: Is it possible to send CAN frames with different IDs with a single Mailbox configured?

Eric FOURRIER

Part Number: TMS320F28388D

Hello,

I declare a single mailbox as output (extended mode with IT TXIE):

with id_base = frame ID: 0x18FF50E5 and SC_CAN_NUMMAILBOX_TX = num Mailbox: 1

Then I want to send two consecutive frames via the same num Mailbox but with a different frame ID: the first ID = 0x18FF50E5 the second with ID 0x18FF51E5 .

Both frames have the same ID:

I wanted to use the CAN_sendMessage_updateDLC function because the two frames have two different DLCs.

I tried to make my own function from this one: CAN_sendMessage_updateMsgIdMsgDLC to add the identifier as an argument, writing it to the CAN_IF1ARB register:

The ID has the desired address: 0x18FF51E5 But the frame actually output retains the initial address inserted viia CAN_setupMessageObject

So, is it possible to transmit CAN frames with different IDs with a single Mailbox configured as output?

Thanks for your help.

Eric

over 1 year ago

0 Sahil Deshpande over 1 year ago

TI__Expert 6035 points

Eric,

Will get back to you on this by tomorrow.

Thanks.

0 Eric FOURRIER over 1 year ago in reply to Sahil Deshpande

Prodigy 50 points

Hi Sahi,

ok I'm waiting your feedback.

Regards,

Eric

0 Sahil Deshpande over 1 year ago

TI__Expert 6035 points

Eric,

Eric FOURRIER said:
I tried to make my own function from this one: CAN_sendMessage_updateMsgIdMsgDLC to add the identifier as an argument, writing it to the CAN_IF1ARB register

The process of writing to any message object involves updating the arbitration register AND then writing to the command register (CAN_IF1CMD) with Dir bit set to 1.

Eric FOURRIER said:
So, is it possible to transmit CAN frames with different IDs with a single Mailbox configured as output?

It is possible. I can provide you with a validated function for this by Wednesday, 21st February.

Thanks.

+1 Eric FOURRIER over 1 year ago in reply to Sahil Deshpande

Prodigy 50 points

Hi Sahil,

thank you for your reply.

Sahil Deshpande said:
The process of writing to any message object involves updating the arbitration register AND then writing to the command register (CAN_IF1CMD) with Dir bit set to 1.

it seems to me that's what I'm doing, but probably badly:

static void CAN_sendMessage_updateMsgIdMsgDLC(uint32_t base, uint32_t objID,
                                              SC_CAN_frame_type_t msgType, uint32_t msgID,
                                              uint16_t msgLen, const uint8_t *msgData)
{
    uint32_t arbReg = 0U;
    uint32_t msgCtrl = 0U;

    //
    // Check the arguments.
    //
    ASSERT(CAN_isBaseValid(base));
    ASSERT((objID <= 32U) && (objID > 0U));
    ASSERT(msgLen <= 8U);

    //
    // Set IF command to read message object control value
    //
    // Set up the request for data from the message object.
    // Transfer the message object to the IF register.
    //
    HWREG_BP(base + CAN_O_IF1CMD) = ((uint32_t)CAN_IF1CMD_CONTROL |
                                     (objID & CAN_IF1CMD_MSG_NUM_M));

    //
    // Wait for busy bit to clear
    //
    while((HWREGH(base + CAN_O_IF1CMD) & CAN_IF1CMD_BUSY) == CAN_IF1CMD_BUSY)
    {
    }

    //
    // Read IF message control
    //
    msgCtrl = HWREGH(base + CAN_O_IF1MCTL);

    //------
    // Modif EF add "ID"
    //-----
    
    arbReg = CAN_IF1ARB_DIR; // Sens Tx
    //
    // Set values based on Extended Frame or Standard Frame
    //
    if(msgType == SC_CAN_FRAME_TYPE_DATA_EXT)
    {
        //
        // Set the 29 bit version of the Identifier for this message
        // object. Mark the message as valid and set the extended ID bit.
        //
        arbReg |= (msgID & CAN_IF1ARB_ID_M) | CAN_IF1ARB_MSGVAL |
                  CAN_IF1ARB_XTD;
    }
    else
    {
        //
        // Set the 11 bit version of the Identifier for this message
        // object. The lower 18 bits are set to zero. Mark the message as
        // valid.
        //
        arbReg |= ((msgID << CAN_IF1ARB_STD_ID_S) & CAN_IF1ARB_STD_ID_M) |
                  CAN_IF1ARB_MSGVAL;
    }
    HWREG_BP(base + CAN_O_IF1ARB) = arbReg;
    // End Modif EF of add "ID"
    //-----

    //
    // Update to the new data length
    //
    msgCtrl &= ~CAN_IF1MCTL_DLC_M;
    msgCtrl |= (msgLen & CAN_IF1MCTL_DLC_M);

    //
    // Write out to the register to program the message object
    //
    HWREG_BP(base + CAN_O_IF1MCTL) = msgCtrl;

    //
    // Transfer data to message object RAM
    //
    HWREG_BP(base + CAN_O_IF1CMD) =
        (CAN_IF1CMD_CONTROL | CAN_IF1CMD_DIR | (objID & CAN_IF1CMD_MSG_NUM_M));

    //
    // Wait for busy bit to clear
    //
    while((HWREGH(base + CAN_O_IF1CMD) & CAN_IF1CMD_BUSY) == CAN_IF1CMD_BUSY)
    {
    }

    //
    // Set IF command to read message object control value
    //
    // Set up the request for data from the message object.
    // Transfer the message object to the IF register.
    //
    HWREG_BP(base + CAN_O_IF1CMD) = ((uint32_t)CAN_IF1CMD_CONTROL |
                                     (objID & CAN_IF1CMD_MSG_NUM_M));

    //
    // Wait for busy bit to clear
    //
    while((HWREGH(base + CAN_O_IF1CMD) & CAN_IF1CMD_BUSY) == CAN_IF1CMD_BUSY)
    {
    }

    //
    // Read IF message control
    //
    msgCtrl = HWREGH(base + CAN_O_IF1MCTL);

    //
    // Check provided DLC size with actual Message DLC size
    //
    ASSERT((msgCtrl & CAN_IF1MCTL_DLC_M) == msgLen);

    //
    // Write the data out to the CAN Data registers.
    //
    CAN_writeDataReg(msgData, (base + CAN_O_IF1DATA),
                     (msgCtrl & CAN_IF1MCTL_DLC_M));

    //
    //  Set Data to be transferred from IF
    //
    if(msgLen > 0U)
    {
        msgCtrl = CAN_IF1CMD_DATA_B | CAN_IF1CMD_DATA_A;
    }
    else
    {
        msgCtrl = 0U;
    }

    //
    // Set Direction to write
    //
    // Set Tx Request Bit
    //
    // Transfer the message object to the message object specified by
    // objID.
    //

    HWREG_BP(base + CAN_O_IF1CMD) = (msgCtrl | (uint32_t)CAN_IF1CMD_DIR |
                                     (uint32_t)CAN_IF1CMD_TXRQST |
                                     (objID & CAN_IF1CMD_MSG_NUM_M));
}

OK to receive your function on Wednesday 21, thank you.

Regards,

Eric

+1 Sahil Deshpande over 1 year ago in reply to Eric FOURRIER

TI__Expert 6035 points

Eric,

I have modified your function and have been able to validate it.

static void CAN_sendMessage_updateMsgIdMsgDLC(uint32_t base, uint32_t objID,
                                              SC_CAN_frame_type_t msgType, uint32_t msgID,
                                              uint16_t msgLen, const uint8_t *msgData)
{
    uint32_t arbReg = 0U;
    uint32_t msgCtrl = 0U;

    //
    // Check the arguments.
    //
    ASSERT(CAN_isBaseValid(base));
    ASSERT((objID <= 32U) && (objID > 0U));
    ASSERT(msgLen <= 8U);

    //
    // Set IF command to read message object control value
    //
    // Set up the request for data from the message object.
    // Transfer the message object to the IF register.
    //
    HWREG_BP(base + CAN_O_IF1CMD) = ((uint32_t)CAN_IF1CMD_CONTROL |
                                     (objID & CAN_IF1CMD_MSG_NUM_M));

    //
    // Wait for busy bit to clear
    //
    while((HWREGH(base + CAN_O_IF1CMD) & CAN_IF1CMD_BUSY) == CAN_IF1CMD_BUSY)
    {
    }

    //
    // Read IF message control
    //
    msgCtrl = HWREGH(base + CAN_O_IF1MCTL);

    //------
    // Modif EF add "ID"
    //-----
    
    arbReg = CAN_IF1ARB_DIR; // Sens Tx
    //
    // Set values based on Extended Frame or Standard Frame
    //
    if(msgType == SC_CAN_FRAME_TYPE_DATA_EXT)
    {
        //
        // Set the 29 bit version of the Identifier for this message
        // object. Mark the message as valid and set the extended ID bit.
        //
        arbReg |= (msgID & CAN_IF1ARB_ID_M) | CAN_IF1ARB_MSGVAL |
                  CAN_IF1ARB_XTD;
    }
    else
    {
        //
        // Set the 11 bit version of the Identifier for this message
        // object. The lower 18 bits are set to zero. Mark the message as
        // valid.
        //
        arbReg |= ((msgID << CAN_IF1ARB_STD_ID_S) & CAN_IF1ARB_STD_ID_M) |
                  CAN_IF1ARB_MSGVAL;
    }
    HWREG_BP(base + CAN_O_IF1ARB) = arbReg;
    // End Modif EF of add "ID"
    //-----

    //
    // Update to the new data length
    //
    msgCtrl &= ~CAN_IF1MCTL_DLC_M;
    msgCtrl |= (msgLen & CAN_IF1MCTL_DLC_M);

    //
    // Write out to the register to program the message object
    //
    HWREG_BP(base + CAN_O_IF1MCTL) = msgCtrl;

    //
    // Transfer data to message object RAM
    //
    HWREG_BP(base + CAN_O_IF1CMD) =
        (CAN_IF1CMD_CONTROL | CAN_IF1CMD_DIR | CAN_IF1CMD_ARB | (objID & CAN_IF1CMD_MSG_NUM_M));                // Set bit to transfer arbitration bits to message object

    //
    // Wait for busy bit to clear
    //
    while((HWREGH(base + CAN_O_IF1CMD) & CAN_IF1CMD_BUSY) == CAN_IF1CMD_BUSY)
    {
    }

    //
    // Set IF command to read message object control value
    //
    // Set up the request for data from the message object.
    // Transfer the message object to the IF register.
    //
    HWREG_BP(base + CAN_O_IF1CMD) = ((uint32_t)CAN_IF1CMD_CONTROL |
                                     (objID & CAN_IF1CMD_MSG_NUM_M));

    //
    // Wait for busy bit to clear
    //
    while((HWREGH(base + CAN_O_IF1CMD) & CAN_IF1CMD_BUSY) == CAN_IF1CMD_BUSY)
    {
    }

    //
    // Read IF message control
    //
    msgCtrl = HWREGH(base + CAN_O_IF1MCTL);

    //
    // Check provided DLC size with actual Message DLC size
    //
    ASSERT((msgCtrl & CAN_IF1MCTL_DLC_M) == msgLen);

    //
    // Write the data out to the CAN Data registers.
    //
    CAN_writeDataReg(msgData, (base + CAN_O_IF1DATA),
                     (msgCtrl & CAN_IF1MCTL_DLC_M));

    //
    //  Set Data to be transferred from IF
    //
    if(msgLen > 0U)
    {
        msgCtrl = CAN_IF1CMD_DATA_B | CAN_IF1CMD_DATA_A;
    }
    else
    {
        msgCtrl = 0U;
    }

    //
    // Set Direction to write
    //
    // Set Tx Request Bit
    //
    // Transfer the message object to the message object specified by
    // objID.
    //

    HWREG_BP(base + CAN_O_IF1CMD) = (msgCtrl | (uint32_t)CAN_IF1CMD_DIR |
                                     (uint32_t)CAN_IF1CMD_TXRQST |
                                     (objID & CAN_IF1CMD_MSG_NUM_M));
}

Please let me know if you run into any issues using this function.

Thanks.

0 Eric FOURRIER over 1 year ago in reply to Sahil Deshpande

Prodigy 50 points

Hello Sahil,

thank you very much for your help, and sorry to reply so late, I was out of office last week.

Your modification has corrected my problem!

Best Regards,

Eric

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TMS320F28388D: Is it possible to send CAN frames with different IDs with a single Mailbox configured?