• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 34 subscribers
  • Views 253 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TCAN1043A-Q1: mode recognition and the controller of TCAN1043A-Q1

Hazel Sun
Expert 6535 points
Part Number: TCAN1043A-Q1

Hi team,

  • How the MCU recognizes whether the TCAN1043A - Q1 operates in typical high speed can modes (e.g., 500Kbps) or can FD modes (e.g., 8Mbps)
  • In the typical application circuit diagram in the specification document, The CAN controller of the MCU is “CAN FD Controller”, as shown in the red circle below， if the MCU does not have a can FD Controller, only a classical CAN Controller， can the classical CAN Controller of the MCU communicate with the TCAN1043A-Q1 normally, or must the CAN controller of the MCU be a CAN FD Controller for proper communication with TCAN1043A-Q1?
  • 0
    TI__Guru 74252 points

    Hazel,

    Thanks for bringing these questions to E2E.

    • There is no difference from a transceiver perspective between typical high speed modes or CAN FD modes. In either case, the transceiver is just used to translate the logic from the controller into a CAN bus signal.
    • Yes, the TCAN1043A-Q1 is compatible with both classical CAN and CAN FD message frames. 

    All TI TCAN transceivers work with both classical CAN and CAN FD frames. The controller is the determining factor for classical and CAN FD frames, the only thing that matters from the physical layer perspective is if the CAN bus driver can drive the correct edge rates and bit widths to meet the data rate requirements for CAN FD.

    Please let me know if you have any other questions.

    Regards,

    Eric Hackett 

  • 0 in reply to Eric Hackett
    TI__Expert 6535 points

    Hi Eric,

    Thank you for your support! I have another question as below:

    If MCU with a classical CAN controller is connected to TCAN1043A-Q1, TCAN1043A-Q1 will work in classical high speed  CAN mode, if MCU with a CAN  FD controller is connected to TCAN1043A-Q1, TCAN1043A-Q1 can  work in classical high speed CAN mode or CAN FD mode, MCU can control which mode it works in through the UART bus(TXD/RXD), is it right?

  • 0 in reply to Hazel Sun
    TI__Guru 53555 points

    Hi Hazel,

    The only difference between classic CAN frames and CAN FD frames is the data rate used for the data portion of the frame. The serial data from the MCU's pin drives the TXD line at a given frequency depending on which portion of the CAN frame is currently being driven. All the transceiver does is translate the data on its TXD pin to the CAN bus and back to RXD. The CAN transceiver does not care about the data contents as long as it is below the maximum speed supported by the device. For this reason, the transceiver can support both classic CAN and CAN FD frames without having to know which is being used. 

    Also keep in mind that the protocol used for CAN is defined by the ISO 11898 standard. Using a different protocol such as UART may require special considerations to ensure compatibility with the CAN physical layer. 

    Regards,
    Eric Schott