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Re: Cortex-Mx MCUs with SWD access locked

From pozz <pozzugno@gmail.com>
Newsgroups comp.arch.embedded
Subject Re: Cortex-Mx MCUs with SWD access locked
Date 2022-06-24 16:56 +0200
Organization A noiseless patient Spider
Message-ID <t94jbb$c8d$1@dont-email.me> (permalink)
References <t92mgi$d1l$1@dont-email.me> <t93vu7$ukp$1@dont-email.me> <sler5kcfj7pp.q0ov9m80226w$.dlg@40tude.net> <t94hld$u4k$2@dont-email.me> <1s43q2growcwa.s2laxcbccg5n$.dlg@40tude.net>

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Il 24/06/2022 16:42, dalai lamah ha scritto:
> Un bel giorno pozz digitò:
> 
>>> Or maybe some ground loops, for example if you have connected the J-Link
>>> probe to a desktop PC (or in general a PC not isolated from mains) and your
>>> boards are somewhat connected to mains or earth ground too.
>>
>> Yes, I use a desktop PC connected to mains and the boards are supplied
>> from an AC/DC connected to mains too.
>>
>> Is this a problematic scenario?
> 
> Normally it shouldn't be, but it also depends on what the board does. If it
> contains some power stages running at high frequency, it is quite common
> (especially if the EMI filtering is subpar) that switching currents can
> pass through the AC/DC power supply and create problems.

The target board power input is 12Vdc and on-board DC/DC (TPS54231, 
570kHz) generates a single 3.3V.


> If this keeps happening, try using a laptop isolated from mains and see if
> it helps.

I hate laptop as development machine, I will try some USB and/or 
debugger isolator. However I imaging the problem would arise with 
oscilloscope, UART/USB converter and so on.

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Thread

Cortex-Mx MCUs with SWD access locked pozz <pozzugno@gmail.com> - 2022-06-23 23:38 +0200
  Re: Cortex-Mx MCUs with SWD access locked pozz <pozzugno@gmail.com> - 2022-06-24 11:25 +0200
    Re: Cortex-Mx MCUs with SWD access locked dalai lamah <antonio12358@hotmail.com> - 2022-06-24 12:22 +0200
      Re: Cortex-Mx MCUs with SWD access locked pozz <pozzugno@gmail.com> - 2022-06-24 16:27 +0200
        Re: Cortex-Mx MCUs with SWD access locked dalai lamah <antonio12358@hotmail.com> - 2022-06-24 16:42 +0200
          Re: Cortex-Mx MCUs with SWD access locked pozz <pozzugno@gmail.com> - 2022-06-24 16:56 +0200
            Re: Cortex-Mx MCUs with SWD access locked dalai lamah <antonio12358@hotmail.com> - 2022-06-24 17:16 +0200
          Re: Cortex-Mx MCUs with SWD access locked David Brown <david.brown@hesbynett.no> - 2022-06-24 18:26 +0200
            Re: Cortex-Mx MCUs with SWD access locked Dimiter_Popoff <dp@tgi-sci.com> - 2022-06-24 20:00 +0300
            Re: Cortex-Mx MCUs with SWD access locked pozz <pozzugno@gmail.com> - 2022-06-27 08:54 +0200
              Re: Cortex-Mx MCUs with SWD access locked David Brown <david.brown@hesbynett.no> - 2022-06-27 09:23 +0200
    Re: Cortex-Mx MCUs with SWD access locked David Brown <david.brown@hesbynett.no> - 2022-06-24 14:15 +0200
      Re: Cortex-Mx MCUs with SWD access locked pozz <pozzugno@gmail.com> - 2022-06-24 16:25 +0200
        Re: Cortex-Mx MCUs with SWD access locked Stef <me@this.is.invalid> - 2022-06-24 20:29 +0200
          Re: Cortex-Mx MCUs with SWD access locked David Brown <david.brown@hesbynett.no> - 2022-06-24 20:34 +0200
            Re: Cortex-Mx MCUs with SWD access locked Stef <me@this.is.invalid> - 2022-06-24 22:12 +0200
              Re: Cortex-Mx MCUs with SWD access locked David Brown <david.brown@hesbynett.no> - 2022-06-25 10:19 +0200
          Re: Cortex-Mx MCUs with SWD access locked pozz <pozzugno@gmail.com> - 2022-06-27 09:06 +0200
            Re: Cortex-Mx MCUs with SWD access locked David Brown <david.brown@hesbynett.no> - 2022-06-27 09:25 +0200
        Re: Cortex-Mx MCUs with SWD access locked Reinhardt Behm <rbehm@hushmail.com> - 2022-06-26 14:25 +0000
          Re: Cortex-Mx MCUs with SWD access locked pozz <pozzugno@gmail.com> - 2022-06-27 10:07 +0200
            Re: Cortex-Mx MCUs with SWD access locked Reinhardt Behm <rbehm@hushmail.com> - 2022-06-27 15:11 +0000
              Re: Cortex-Mx MCUs with SWD access locked pozz <pozzugno@gmail.com> - 2022-06-27 23:50 +0200
                Re: Cortex-Mx MCUs with SWD access locked Stef <me@this.is.invalid> - 2022-06-28 11:23 +0200
                Re: Cortex-Mx MCUs with SWD access locked pozz <pozzugno@gmail.com> - 2022-06-28 12:42 +0200
                Re: Cortex-Mx MCUs with SWD access locked Stef <me@this.is.invalid> - 2022-06-28 17:06 +0200

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