• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 83 subscribers
  • Views 796 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.

CAN Bit timing for ARINC

Harman
Expert 7845 points
Other Parts Discussed in Thread: TMS320F28335

Customer is planning to use TMS320F28335 in an aircraft-related program. They need to be able to configure the CAN peripheral to conform with ARINC 825. The ARINC 825 specifies the following requirements:
1) The SJW (Synchronization Jump Width) SHALL be one time quanta.
2) The sample point SHALL not be less than 75% of the bit time width.
3) Only one sample point SHALL be used.

How do you setup the CAN Bit Timing Configuration register to satisfy these requirements?

  • 0
    TI__Guru* 95315 points

    Harman,

    1) Default value of SJW is 1. This can be increased if needed.

    2) This depends on how TSEG1 & TSEG2 are configured. Here are some examples:

    BT = 10, TSEG1 = 6, TSEG2 = 1, Sampling Point = 80%

    The table below shows how to achieve different sampling points with a BT of 20:
    ------------------------------------------------------------
    Achieving desired SP by changing TSEG1 & TSEG2 with BT = 20
    ------------------------------------------------------------

    TSEG1(reg) = 15, TSEG2(reg) = 2, SP = 85%
    TSEG1(reg) = 14, TSEG2(reg) = 3, SP = 80%
    TSEG1(reg) = 13, TSEG2(reg) = 4, SP = 75%

    3) By default, this is 1 as well.

     

  • 0 in reply to Hareesh Janakiraman
    Prodigy 170 points

    Hi..

    we are trying to implement ARINC 825 protocol with TMS320F28335 for airborne use.

    Can anyone tell me how can I configure baudrate, GPIOs, CAN-port, mailboxes with Message ID and length by using Function pointers in C programming.