Flashing on PCB gives Unknown Error in J-Link DLL

[SohamGhugare]

Hey Team,

I'm trying to flash the audio application on our custom PCB, this PCB follows the interfaces of the nrf5340 audio dk. Previously on lower SDK versions (2.7-2.9), I was able to flash my programs without any errors. However now with the newer toolchain version (3.0.1), Im getting this error whenever i run the west flash command

Command:

`west flash -d /opt/nordic/ncs/v3.0.1/nrf/applications/nrf5340_audio/build --domain nrf5340_audio --dev-id 801055229 --recover`

Logs:

Flashing nrf5340_audio to 801055229
west flash -d /opt/nordic/ncs/v3.0.1/nrf/applications/nrf5340_audio/build --domain nrf5340_audio --dev-id 801055229 --recover

-- west flash: rebuilding
[0/10] Performing build step for 'ipc_radio'
ninja: no work to do.
[1/10] Performing build step for 'nrf5340_audio'
ninja: no work to do.
[4/10] cd /opt/nordic/ncs/v3.0.1/nrf/applications/nrf5340_audio/build/_sysbuild && /opt/nordic/ncs/toolchains/ef4fc6722e/Cellar/cmake/3.21.0/bin/cmake -E true
[6/9] No install step for 'nrf5340_audio'
[7/9] Completed 'nrf5340_audio'
[8/9] cd /opt/nordic/ncs/v3.0.1/nrf/applications/nrf5340_audio/build/_sysbuild && /opt/nordic/ncs/toolchains/ef4fc6722e/Cellar/cmake/3.21.0/bin/cmake -E true
-- west flash: using runner nrfutil
-- runners.nrfutil: reset after flashing requested
-- runners.nrfutil: Recovering and erasing flash memory for both the network and application cores.
-- runners.nrfutil: Flashing file: /opt/nordic/ncs/v3.0.1/nrf/applications/nrf5340_audio/build/merged.hex
-- runners.nrfutil: Recover
-- runners.nrfutil: Recover
-- runners.nrfutil: Erasing address ranges touched by firmware
Error: One or more batch tasks failed:
 * 801055229: Device error: Emulator error: Unknown Error in J-Link DLL (error code =-1) (Generic)

FATAL ERROR: command exited with status 1: nrfutil --json device x-execute-batch --batch-path /opt/nordic/ncs/v3.0.1/nrf/applications/nrf5340_audio/build/generated_nrfutil_batch.json --serial-number 801055229

Sometimes I also get this error randomly

Error: One or more batch tasks failed:
 * 801055229: Device error: Failed to read from memory address 0x500038e4: Failed to write DebugPort register 0x08: Unknown Error in J-Link DLL (error code =-1) (Generic)

What should be the cause of this error and how do I fix it? Please let me know if you require any further information.

PS: Relevant information about the PCB like schematics and stuff are already shared in the private threads with this same account. 

Regards,

Soham

[Menon]

Hello,

I am not completely sure what is causing the issue. From the error log, it looks like a problem related to J-Link. This could be due to an issue with the J-Link connection, firmware, or compatibility between the J-Link software and the target device.

Try updating or reinstalling the J-Link drivers, ensuring firmware compatibility, and also try power cycling the debugger.

Also, take a look at this thread and see if you are facing a similar issue. A workaround has been mentioned there, see if that resolves your problem.

Kind regards,
Abhijith

[SohamGhugare]

Apparently the newer sdk versions just broke a lot of stuff for me, now when I flash the audio application on the nrf5340 Audio DK, I get this fatal error which wasnt occuring before the update

SEGGER J-Link V8.32 - Real time terminal output
SEGGER J-Link (unknown) V1.0, SN=1050161689
Process: JLinkExe
*** Booting nRF Connect SDK v3.0.1-9eb5615da66b ***
*** Using Zephyr OS v4.0.99-77f865b8f8d0 ***
HL [00:00:00.433,013] <inf> board_version: Compatible board/HW version found: 1.1.0
HL [00:00:00.466,064] <inf> fw_info: 
         nRF5340 Audio nRF5340 Audio DK cpuapp              
         NCS base version: 3.0.1                            
         Cmake run : Mon Jun 16 16:29:32 2025
HL [00:00:00.466,064] <inf> fw_info: ------- DEBUG BUILD -------
HL [00:00:00.466,064] <inf> fw_info: HEADSET left device
HL [00:00:02.470,092] <err> bt_hci_driver: Endpoint binding failed with -11
HL [00:00:02.470,092] <err> bt_hci_core: HCI driver open failed (-11)
HL [00:00:02.470,092] <err> main: ERR_CHK Err_code: [-11] @ line: 532
HL [00:00:02.470,123] <err> os: r0/a1:  0x00000003  r1/a2:  0x00000003  r2/a3:  0x00000002
HL [00:00:02.470,123] <err> os: r3/a4:  0x00000003 r12/ip:  0x20003e98 r14/lr:  0x00061629
HL [00:00:02.470,123] <err> os:  xpsr:  0x09100000
HL [00:00:02.470,123] <err> os: s[ 0]:  0x20002780  s[ 1]:  0x000617e1  s[ 2]:  0x2001e428  s[ 3]:  0x00000004
HL [00:00:02.470,153] <err> os: s[ 4]:  0xffffffff  s[ 5]:  0x0003bdf1  s[ 6]:  0x0003bdf1  s[ 7]:  0x2001e458
HL [00:00:02.470,153] <err> os: s[ 8]:  0x2001e428  s[ 9]:  0xffffffff  s[10]:  0xffffffff  s[11]:  0x00061825
HL [00:00:02.470,153] <err> os: s[12]:  0x0003bdf1  s[13]:  0x00072bb8  s[14]:  0xfffffff5  s[15]:  0x00000214
HL [00:00:02.470,184] <err> os: fpscr:  0x0003bdf1
HL [00:00:02.470,184] <err> os: Faulting instruction address (r15/pc): 0x00004a5c
HL [00:00:02.470,214] <err> os: >>> ZEPHYR FATAL ERROR 3: Kernel oops on CPU 0
HL [00:00:02.470,214] <err> os: Current thread: 0x20006228 (main)
HL [00:00:02.470,214] <err> error_handler: Caught system error -- reason 3. Entering infinite loop

Backtracking with addr2line, the error occurs in

// unicast_server/main:531

ret = bt_mgmt_init();

What is causing this?

PS: This started occuring after i upgraded the nrfutl device recently