[SOLVED] Halt in Ozone change ETM clock

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  • [SOLVED] Halt in Ozone change ETM clock

    Hello,

    I use the J-Trace Pro to trace a SAMe70q21 with Ozone. The trace clock is generated with the PMC_PCK[3] unit.
    After a few seconds I see trace overflow problems and trace clock is 25MHz.
    So I change the prescaler of PMC_PCK[3] to a trace clock of 50MHz writing the clock register in c-code during startup.
    Trace clock display in the J-Trace Pro Webserver is then 50MHz and trace is running fine until I halt the system.
    When I press continue in Ozone gui "something" change the prescaler back to a trace clock of 25MHz --> overflow.

    How to keep Ozone away form this prescaler setup?
    I try this also with atmel studio and J-Trace Pro. No change of this prescaler value.

    Regards, Dave

  • Hello Dave,

    Thank you for your inquiry.
    The example project from our Wiki uses MCK as PCK clock source and divides it by 2 resulting in 75 MHz trace clock speed: wiki.segger.com/Tracing_on_Atmel_ATSAME70
    If you use the .pex file from that project for your setup these settings will be applied on each trace start.
    Did you change the PCK clock source as well?

    Best regards,
    Nino
    Please read the forum rules before posting.

    Keep in mind, this is *not* a support forum.
    Our engineers will try to answer your questions between their projects if possible but this can be delayed by longer periods of time.
    Should you be entitled to support you can contact us via our support system: segger.com/ticket/
    Or you can contact us via e-mail.

  • Hello Nino,

    I try the .pex file in the trace example. This one works fine. MCK/2 for trace clock.
    But the pex file in the SEGGER\Ozone V2.60k\Devices\ATMEL\Atmel_SAME70.pex does MCK/4 for trace clock -> overflow.
    This is really tricky, because I am unable to read the difference between the two files.
    Is it possible to get a "human readable" version of the two files to see the difference?

    So thank you very much for your help.
    Regards, Dave.

  • Hello Dave,

    Thank you for the additional information, this made things clear.
    The default pex file will set PCK to MCK/15 as SWO clock derives from that clock as well and we needed to make sure that SWO would work out-of-the-box.
    Unfortunately the trace clock also gets derived from PCK so having SWO and ETM tracing running at the same time there is essentially a trade of between SWO and ETM to be made if they should be used at the same time.
    If you only are looking to use ETM then simply use the .pex from the Wiki. We will see if we can improve documentation in our Wiki about the SAME70 series that explains this premise better.

    Dave wrote:

    Is it possible to get a "human readable" version of the two files to see the difference?
    Yes this is possible, however not on this public forum.
    Could you contact us in our support ticket system regarding the JLinkScript source for the SAME70?
    You can find the link in my signature.

    Best regards,
    Nino
    Please read the forum rules before posting.

    Keep in mind, this is *not* a support forum.
    Our engineers will try to answer your questions between their projects if possible but this can be delayed by longer periods of time.
    Should you be entitled to support you can contact us via our support system: segger.com/ticket/
    Or you can contact us via e-mail.