[SOLVED] SWO usage

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  • [SOLVED] SWO usage

    Hi,
    I am using Ozone connected with a Nordic nRF52840 based target via Segger JLink Plus (using the SWD interface). The trace pins currently are available, but not used because I don't have a JTrace adapter. We are now discussing about a new hardware revision which might exclude the use of SWO because the pin is needed for another peripheral chip (spi flash).
    My question is: will loosing the SWO pin restrict my debug possibilities? As far as I know, all communication between JLink and target is done via SWD and none using the SWO. I included the Segger RTT library from the Nordic SDK5, but from my understanding, this also comunicates via SWD.
    Regards
    Dirk
  • Hi,
    It will of course prevent your from using SWO, which is technically a restriction of your debug possibilities.

    The SWO pin is solely used for transmitting SWO data (ITM + ITM_printf()).
    If you are not using SWO anyway, it will not affect your debug setup.

    Does this answer your question?
    Best regards,
    Fabian
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  • Thank you Fabian!
    > Does this answer your question?
    Hm, I hope. I simply want to ensure I don't overlook something. Maybe I should have stated the question this way: "If I cannot use ITM, do I loose functionality in Ozone?"
  • Hello,

    in short yes.
    But if you are going for pin tracing anyhow you will get many advanced debug features that make any feature the ITM would bring obsolete.

    If you planned on using SWO for printf we recommend using RTT instead. Then also the SWO pin is not needed:
    segger.com/products/debug-prob…about-real-time-transfer/

    So effectively you do not loose any debug functionality.

    Best regards,
    Nino
    Please read the forum rules before posting: Forum Rules

    Keep in mind, this is not a support forum. Its main purpose is user to user interaction.
    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.