• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 82 subscribers
  • Views 179 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

TMS320F28235-Q1: CAN module arbitration

Jordan Zhou
Genius 9700 points
Part Number: TMS320F28235-Q1
Other Parts Discussed in Thread: CONTROLSUITE

Hi,

During CAN initialization, bit CCE (in register CANES) is 0, no mater CANRX is high or low. 

From oscilloscope, CANRX pin is always highafter power on. Few times, there's a low pulse. 

What could be the issue?

Some other doubts about CAN:

1) Is there any register to show the status of arbitration?

2) Is there any register to show the automatic retransmission?

Thanks a lot.

Br, Jordan

  • 0
    TI__Guru* 95315 points
    Jordan Zhou said:
    During CAN initialization, bit CCE (in register CANES) is 0, no mater CANRX is high or low. 

    You mean even after setting CCR bit, CCE bit never becomes 1? Do you see this issue even when you run the TI-provided examples in Controlsuite? Have you tried the examples in www.ti.com/lit/spra876? Did you look at the debug tips?

    Jordan Zhou said:
    From oscilloscope, CANRX pin is always highafter power on. Few times, there's a low pulse. 

    When the bus is idle, CANRX pin will be high. This is normal and to be expected. The few times you see a low pulse is likely legitimate CAN traffic. However, note that whatever you observe must conform to the protocol bit-stuffing rules. That is, within a CAN frame, there cannot be a high or low period that is longer than 5 bit-times.

    Jordan Zhou said:
    1) Is there any register to show the status of arbitration?

    No.

    Jordan Zhou said:
    2) Is there any register to show the automatic retransmission?

    No.