TMS320F28388D: Implementing DCAN FIFO on F28388D

1. I didn’t even see a DCAN transmit FIFO demo, does this kind of FIFO exist or not?

No, we don’t have this example in C2000Ware, as of now. 

2. Typically, we are using a FIFO to reduce the times for CPU to response an interrupt. If we already programming DCAN using Tx or Rx interrupts, will it still be beneficial to using a FIFO? I ask this for I didn’t find an interrupt configuration specially designed for FIFO mode like a SCI or SPI.

What do you do when the FIFO is filled?

Hi Hareesh,

Currently, I don't know what event can be triggered with a CAN receive FIFO is filled. So I just read the first mail box and move the receive buffer as shown below.

    else if(status == RX_MSG_OBJ_ID)
    {
        //
        // Get the received message
        //
        // CAN_readMessage(CANA_BASE, RX_MSG_OBJ_ID, rxMsgData);


        CAN_readMessage(CANA_BASE, RX_MSG_OBJ_ID, rxbuffer_pointer);
        if(i == 3){
            __asm("   bkpt #0");
        }else{
            rxbuffer_pointer = rxbuffer_pointer + 4;
        }
        i ++;

        //
        // Getting to this point means that the RX interrupt occurred on
        // message object 2, and the message RX is complete.  Clear the
        // message object interrupt.
        //
        CAN_clearInterruptStatus(CANA_BASE, RX_MSG_OBJ_ID);

        //
        // Increment a counter to keep track of how many messages have been
        // received. In a real application this could be used to set flags to
        // indicate when a message is received.
        //
        rxMsgCount++;

        //
        // Since the message was received, clear any error flags.
        //
        errorFlag = 0;

    }

I initialize the FIFO as below:

    //
    // Initialize the receive message object used for receiving CAN messages.
    // Message Object Parameters:
    //      Message Object ID Number: 2
    //      Message Identifier: 0x1
    //      Message Frame: Standard
    //      Message Type: Receive
    //      Message ID Mask: 0x0
    //      Message Object Flags: Receive Interrupt
    //      Message Data Length: 4 Bytes
    //
    CAN_setupMessageObject(CANA_BASE, RX_MSG_OBJ_ID, 0x1, CAN_MSG_FRAME_STD,
                           CAN_MSG_OBJ_TYPE_RX, 0, CAN_MSG_OBJ_RX_INT_ENABLE | CAN_MSG_OBJ_FIFO,
                           MSG_DATA_LENGTH);

    //
    // Initialize the receive message object used for receiving CAN messages.
    // Message Object Parameters:
    //      Message Object ID Number: 3
    //      Message Identifier: 0x1 (same)
    //      Message Frame: Standard
    //      Message Type: Receive
    //      Message ID Mask: 0x0 (same)
    //      Message Object Flags: Receive Interrupt
    //      Message Data Length: 4 Bytes
    //
    CAN_setupMessageObject(CANA_BASE, RX_MSG_OBJ_ID_0, 0x1, CAN_MSG_FRAME_STD,
                           CAN_MSG_OBJ_TYPE_RX, 0, CAN_MSG_OBJ_RX_INT_ENABLE | CAN_MSG_OBJ_FIFO,
                           MSG_DATA_LENGTH);

    //
    // This receive message object with higher ID number is the last member of a receive FIFO
    //
    // Initialize the receive message object used for receiving CAN messages.
    // Message Object Parameters:
    //      Message Object ID Number: 4
    //      Message Identifier: 0x1 (same)
    //      Message Frame: Standard
    //      Message Type: Receive
    //      Message ID Mask: 0x0 (same)
    //      Message Object Flags: Receive Interrupt
    //      Message Data Length: 4 Bytes
    //
    CAN_setupMessageObject(CANA_BASE, RX_MSG_OBJ_ID_1, 0x1, CAN_MSG_FRAME_STD,
                           CAN_MSG_OBJ_TYPE_RX, 0, CAN_MSG_OBJ_RX_INT_ENABLE,
                           MSG_DATA_LENGTH);

Do you have any recommendation for what to be done when FIFO is filled? Do we have any event to signal a FIFO is filled?

Thanks

Sheldon

Hi Hareesh,

Any updates for my questions here? I'd like to generating an interrupt on receiving all the three message object in one FIFO. How could I do that?

Thanks

Sheldon