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Hae Ryon Jung
Hae Ryon Jung
Associate III
May 28, 2018
Solved

ST-link ISOL lost settings

  • May 28, 2018
  • 7 replies
  • 2695 views
Posted on May 28, 2018 at 12:46

Hi All, 

I have tried to connect my custom target board with ST-link/V2 ISOL.

when I run STM32 ST-Link Utility, it looks OK, setting is captured as follows

0690X00000604bAQAQ.jpg

after connect 20 pin JTAG cable to my custom board, STM32F103RF with empty flash.(I haven't flash it yet)

few seconds later, setting is changed as follows,

0690X00000604bFQAQ.jpg

after error, I have to disconnect and reconnect USB cable connected to PC, and re-run ST-link utility.

Would you please let me know what is wrong with my setting or connection ?

FYI, ST-link/V2 is updated with latest firmware.

Thanks in advance.

Best Regards,

Hae Ryong

    This topic has been closed for replies.
    Best answer by Hae Ryon Jung
    Posted on May 29, 2018 at 06:02

    Hi All, 

    Thanks for your feedback.

    I have found the cause of error, we have designed SWDIO, SWDCLK pin as GPIO for later use, so there are capacitors connected on the line, it may cause signal error.

    When we removed capacitors, ST link worked OK.

    7 replies

    Pavel A.
    Pavel A.
    May 28, 2018
    Posted on May 28, 2018 at 13:25

    Even on the 1st picture the target could not be detected. Not a good sign. 

    Try to lower the frequency?

    -- pa

    Hae Ryon Jung
    Hae Ryon JungAuthor
    Associate III
    May 29, 2018
    Posted on May 29, 2018 at 04:20

    Target -> Settings 

    when I tried to change Frequency at Settings menu, it showed as follows and I could not try connection for error

    0690X00000604W1QAI.jpg
    Tesla DeLorean
    Tesla DeLorean
    Guru
    May 28, 2018
    Posted on May 28, 2018 at 14:26

    Is the interface powered via VTarget on pin 1 or 2?

    Tips, Buy me a coffee, or three.. PayPal Venmo (See Profile) Up vote any posts that you find helpful, it shows what's working..
    Hae Ryon Jung
    Hae Ryon JungAuthor
    Associate III
    May 29, 2018
    Posted on May 29, 2018 at 03:44

    Connection is as follows

    1, 2 : 3.3V power

    7 : SWDIO

    9 : SWCLK

    15 : NRST

    remains are GND or open

    I have checked NRST pin, when I started connect, then it went to LOW and never went back to HIGH.

    Any Idea about why NRST stays at LOW ?

    Tesla DeLorean
    Tesla DeLorean
    Guru
    May 29, 2018
    Posted on May 29, 2018 at 04:08

    Check VDDA supply, this powers the POR circuit which can clamp NRST low.

    Tips, Buy me a coffee, or three.. PayPal Venmo (See Profile) Up vote any posts that you find helpful, it shows what's working..
    Hae Ryon Jung
    Hae Ryon JungAuthorBest answer
    Associate III
    May 29, 2018
    Posted on May 29, 2018 at 06:02

    Hi All, 

    Thanks for your feedback.

    I have found the cause of error, we have designed SWDIO, SWDCLK pin as GPIO for later use, so there are capacitors connected on the line, it may cause signal error.

    When we removed capacitors, ST link worked OK.

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