cannot find RTT control block

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  • cannot find RTT control block

    I am using FreeRTOS with Sysview.
    whenever I try to start recording I get the message stating that system view cannot find RTT control block
    however if I just click on read data it ALWAYS succeeds.
    what might be a problem?

    thanks,
    Raphael
  • Hi,

    Which target device are you using?
    Is the configuration the same when starting to record as when reading recorded data?

    Best regards
    Johannes
    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/

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  • Then continuously recording is not supported on your device,
    since it does not allow to access memory while the target is running.
    In general this is only possible on Cortex-M, Renesas RX, and some Cortex-A devices.

    The difference between read data and start recording is,
    that with read data the target is halted and the data is read only once.

    Best regards
    Johannes
    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.
  • No Starting or reading

    I'm attempting to use FreeRTOS 9 with 2.38 in the code and 2.40 SystemView (I think) on KDS MK22F part. I've got the project set up with just an Idle task and nothing else. Bare metal past that without turning on anything else. I'm attempting to strip down the project to bare essentials.

    Talking to it with a J-LINK Lite running over SWD. I've got the thing compiled and running. I'm sure systemview is talking to the device as I accidentally left the debugger running and got a breakpoint that indicated it was talking.

    When doing "start recording" I come back immediately with a "Failed to start recording. RTT Control Block Not found"

    if I use the "read recorded data" SystemVIew hangs waiting for something until I pull the USB cable to the J-LINK lite.

    Any hints?
  • I was able to get RTT working on this system. I can send prints to the terminal (J-LINK viewer).

    I was able to get SystemView to grab data with the "Read Recorded Data" after I inserted a SEGGER_SYSVIEW_Start() in the code. I get some variable data out of this: right now it doesn't have time information in it but I have seen it do that and get nice traces.

    I still can't get it to do a record real time.

    The target here is a Freescale MK22F256 part (Cortex M4) so the part shouldn't be the problem.

    Documentation on the site suggests that the J-LINK lite board should be able to do this, but maybe it's wrong and you need an actual J-LINK to do real time recording?
  • Hi,

    When "Read Recorded Data" works, live recording should also work.
    Could you make sure to select the correct device in the configuration dialog and alternatively also set the address of the Control Block manually?

    Regards
    Johannes
    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.