Subsequent Connections to RP2040 Fail

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    • Subsequent Connections to RP2040 Fail

      Hi all, I'm using a J-link Mini Edu to debug firmware on a Raspberry Pi Pico board. If I plug in my J-link, start the GDB server, and load my .ELF file, it will work fine first time. However, if I close the GDB server, rebuild my project, and try to start the GDB server again, it will fail to connect to the RP2040, giving a communication error. If I unplug the USB cable on the J-link and plug it back in again, I am able to connect to the board again. It appears that a full power-down resets something, allowing me to connect again.

      Is there some sort of command I should issue when starting the GDB server or just before closing it to force a reset of the hardware so I don't have to keep unplugging and replugging my USB cable?
    • We also stumbled across this.
      It is currently under investigation.
      We will update this thread, once it is solved.
      It seems to have something to do with SWD multi-drop. Maybe a misbehavior inside the J-Link firmware...

      Keep you posted
    • I am using Ozone with JLInk Edu mini and RP2040 B0.

      Ozone upload is working, but debugging fails after upload. Target reset doesn't help. But disconnect-reconnect JLink helps, after that "attach to running program" is working. It's probably the same subsequent connection problem.

      J_Flash lite: better to use .hex, because the start address is not zero for .bin.
      After erase chip, a target reset required before flashing.

      It's a bit uncomfortable, that no power for the target from the mini, and most of my targets has no standard swi connector. So I put a 3.3V LDO and the mini to a small 3d printed box with 2.54mm pin headers. The yellow jumper connects the 3.3V to VTRef.
    • Hi,
      As Alex already pointed out:
      This issue is known to us and we are currently working on it.

      Regarding the power supply:
      If you want a non-commercial J-Link with target power support, we would recommend the J-Link EDU:
      It comes with a 5V pin, and other beneficial features.

      A comparison between our models can be found here:…erview/#hardware-features

      Even though it is a little bit more expensive then the EDU mini,
      it should still be in an affordable price range for private users / students.

      Best regards,
      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:

      Or you can contact us via e-mail.
    • This issue is still present in 7.20. Since there was no firmware update for the probe I suspected that was the case, but just confirmed it locally. Bumping this in case the issue has fallen off the radar.