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Date of registration: Jan 11th 2018

Posts: 2


Thursday, January 11th 2018, 6:11pm

[ABANDONED] ST-Link to J-Link/J-Trace on STM32L476RC

Hi, trying to switch from ST-Link to J-Link without much success.

A- STM32L476RCTx based custom board
B- OpenSTM32 / AC6 GCC based toolchain
C- Nucleo-64 L476RG based ST-Link v2.1 debugger
D- Using 'STM32 ST-LINK Utility.exe', did a 'Erase Chip'.

0x1FFF7800 = FFEFF8AA 00100755 FFFFFFFF 00000000
0x1FFF7810 = 7FFF0000 8000FFFF FF00FFFF 00FF0000

Works, slow but works (limited to 4 breakpoints though, if you want to have success with 'step out'/'run to')

-> log_stlink.txt

E- Added GNU MCU Eclipse plugin from
F- Made a connector custom bridge…k-stm32-boards/
G- Connected the J-Link, configured a 'GDB SEGGER J-Link Debugging' based configuration (default)

This doesn't work like expected, flash is not performed successfully, PC get stuck somewhere in a rather random place.

H- To be sure it is not a bridge problem, I removed J-Link and switched to ST-Link firmware from…-link-on-board/
I- Executed 'JLinkSTM32.exe' (11) then 'JLink.exe' to get option bytes ('mem32 0x1FFF7800,C')

1FFF7800 = FFEFF8AA 00100755 FFFFFFFF 00000000
1FFF7810 = 7FFF0000 8000FFFF FF00FFFF 00FF0000

Got the same problem.

-> log_jlink_flash.txt

Any idea ?
Noyb has attached the following files:
  • log_stlink.txt (3.73 kB - 44 times downloaded - Last download: May 18th 2018, 6:26pm)
  • log_jlink_flash.txt (7.45 kB - 50 times downloaded - Last download: Today, 12:03am)


Super Moderator

Date of registration: Jan 2nd 2017

Posts: 1,048


Friday, January 12th 2018, 11:09am


Thank you for your inquiry.
Such an issue is not known to us.

To understand your setup correctly, you use the ST-Link on the Nucleo board as debug out to debug an STM32L4 on a custom board?
Is that correct?
Is there a specific reason why not simply use the J-Link you have registered with in the forum?

When using the converted ST-Link, can you connect to the target device at all?
Could you crosscheck this with the J-Link Commander and post your results?…-Link_Commander

Best regards,
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Date of registration: Jan 11th 2018

Posts: 2


Friday, January 12th 2018, 11:14am

Yeah, the original development took place using ST-Link.
I then switched to J-Link/J-Trace (using GNU MCU Eclipse) but no luck.
Tried to switch back to ST-Link but converted to J-Link but no luck either.
So the problem is not the bridge (connector)
Is the problem from the j-Link firmware (option byte, flashing dual bank) ?
I will try J-Link Commander asap.