data sampling / timeline when doing emulated background reads

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    • data sampling / timeline when doing emulated background reads

      given you can refresh watched data at up to a few Hz in the background on MPUs that don't support the full high speed sampling mechanism over JTAG, why does the Timeline / data sampling?

      using J-Trace with Cortex A5D27 which doesn't support the full high speed background refresh

      this appears in the console


      Hardware setup does not support data sampling.
      Current setup does not support background memory access mode
      Error (84): Failed to start high speed sampling (HSS).

      i don't see why the mechanism for flushing the data from the processor should matter to being able to graph / do stats on a variable ( which does appear in the data sampling window but obviously doesn't update ) given that as the user we know and understand the sampling restrictions of the hardware platform
    • Hi AndyR,
      I'm sorry but I am not able to comprehend the point of your inquiry.
      Could you please describe more clearly what exactly you would like to know or understand?
      Best regards
      -- AlexD
      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.
    • you can't graph watched variables when using the emulated background JTAG refreshing [ Cortex A5D27 doesn't support high speed live watches according to ozone so is starting and stopping the MPU to read the values ]

      they do happily slowly update which is fine given you only get 5Hz updating

      but you can't graph the vatiables
    • Hi AndyR,
      please refer to the Ozone user' manual, section 4.6.1, where the hardware requirements for the data sampling window are listed. There you can see that you can control background memory access emulation via the system variable VAR_ALLOW_BMA_EMULATION. Setting this variable correctly should resolve the issue you see.
      In general, if you see the data sampling window populating with data, you should be able to see that content in the data pane of the time line window. If the data sampling window remains empty, data cannot be displayed in the time line window.
      Best regards
      -- AlexD
      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.
    • VAR_ALLOW_BMA_EMULATION is on and has been - hence i said I have seen and understood the massive difference in update rates for this mode of operation being limited to 5Hz but sample rate is no issue for this

      this is what happens when i try and use this

      "tick" is added as a watch, set to refresh at 1Hz and it does indeed update in the watch window at 1Hz

      when then try to graph "tick" then you just spit out a bunch of error messages in the console

      which contradicts what the manual / you say
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    • Hi AndyR,
      could you please provide a J-Link log and an Ozone log, both recorded during the same session where the issue is reproduced?
      How to create an Ozone log is described in chapter 8 of the Ozone user's manual. Creating a J-Link log file is described here: wiki.segger.com/J-Link_DLL#Enable_J-Link_Log_File
      Best regards
      -- AlexD
      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.
    • Hi AndyR,
      on which device, exactly do you observe that behavior?
      We shall try to reproduce locally.
      Best regards
      -- AlexD
      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.