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C164, CA step CAN

hannes mahler

Dear Sirs, Mr. Coppi!

...I use the CAN-Module of a CA-step. Because everything was fine using the Board, I burned it without looking at the errata sheed...I was surprised at the result!
Now I want to please You help me avoid another mistake.

The behavior can be avoided if a message object is not updated by software when a
transmission of the corresponding message object is pending (TXRQ element is set)
and the CAN module is active (INIT = 0).

Does that mean, if I would disable the CAN module each time I change something (data) in an object and enable it after that everything will be o.K.?

The nodes in the CAN system ignore the remote frame with the identifier=0 and no
data frame is triggered by this remote frame.

Is this another or additional possibility?
Is there a way to disable only the identifier '0'?

I'm not so sure if I did understand the errata well, so please don't wonder about this questions.

Do You know about a distributor who could have a flash device of the C164? (It's really expensive for me to burn them so often and this could prevent al least wrong startup configurations other mistakes which are not step-specific?!)

Thanks a lot for helping me
hannes

P.S. why differs the behaviour using the RAM of the Board instead of OTP??

Parents
  • 0 in reply to Bruno Coppi

    Dear Mr. Coppi!
    I gave up to figure out the Problems (e.g. the clock works correct only with jumperconfiguration, allthough i did configure it by software....). I want to please You to write Your opinion to that: i will take the CAN Project i wrote once and burn it. The difference is the use of CA-step instead of DA-step. I think it should work?
    To be sure i will mask out the eleventh bit of the ID arbitration register, so all ID's must be higher than, or equal 0x400 for beeing accepted. By that way i hope to prevent the CAN module for sending request messages with ID '0'(?!)
    I would do because i read this in errata sheet:



    Workarounds:
    • The behavior can be avoided if a message object is not updated by software when a
    transmission of the corresponding message object is pending (TXRQ element is set)
    and the CAN module is active (INIT = 0). If a re-transmission of a message (e.g. after
    lost arbitration or after the occurrence of an error frame) needs to be cancelled, the
    TXRQ element should be cleared by software as soon as NEWDAT is reset from the
    CAN module.

    • The nodes in the CAN system ignore the remote frame with the identifier=0 and no
    data frame is triggered by this remote frame.

    Would be nice if You could help me by that decision (it's really expensive by the time).

    Like i wrote before i wonder about the difference between RAM and Flash memory. I took a look at the schematic of the board and the memories are connected in parallel. So i can't really explain how this could be different. Could it be a reason of waitstates or something like that? (I think the startup of Ram is the same of Flash?) Do You know something? All that seems to me like kind of mystic.
    Do You know literarure, where is written more about the map file, i think i have to learn about these things to be more sure knowing what i'm doing! Sorry, that i reacted so late to your reply- i have to learn for some tests at the moment.

    Thank You!
    Best regards hannes

Reply
  • 0 in reply to Bruno Coppi

    Dear Mr. Coppi!
    I gave up to figure out the Problems (e.g. the clock works correct only with jumperconfiguration, allthough i did configure it by software....). I want to please You to write Your opinion to that: i will take the CAN Project i wrote once and burn it. The difference is the use of CA-step instead of DA-step. I think it should work?
    To be sure i will mask out the eleventh bit of the ID arbitration register, so all ID's must be higher than, or equal 0x400 for beeing accepted. By that way i hope to prevent the CAN module for sending request messages with ID '0'(?!)
    I would do because i read this in errata sheet:



    Workarounds:
    • The behavior can be avoided if a message object is not updated by software when a
    transmission of the corresponding message object is pending (TXRQ element is set)
    and the CAN module is active (INIT = 0). If a re-transmission of a message (e.g. after
    lost arbitration or after the occurrence of an error frame) needs to be cancelled, the
    TXRQ element should be cleared by software as soon as NEWDAT is reset from the
    CAN module.

    • The nodes in the CAN system ignore the remote frame with the identifier=0 and no
    data frame is triggered by this remote frame.

    Would be nice if You could help me by that decision (it's really expensive by the time).

    Like i wrote before i wonder about the difference between RAM and Flash memory. I took a look at the schematic of the board and the memories are connected in parallel. So i can't really explain how this could be different. Could it be a reason of waitstates or something like that? (I think the startup of Ram is the same of Flash?) Do You know something? All that seems to me like kind of mystic.
    Do You know literarure, where is written more about the map file, i think i have to learn about these things to be more sure knowing what i'm doing! Sorry, that i reacted so late to your reply- i have to learn for some tests at the moment.

    Thank You!
    Best regards hannes

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