Hello,

couple of weeks ago I bought JLink Edu Mini for hobby projects. Since then I am unable to debug or flash using it.

I have tried to debug and flash RPi Pico and STM32F429ZI discovery board.

For Pi Pico it only showed messages about ConfigTargetSettings() and never got connected.

For STM32F429, with SWD interface on STM32CubeIDE I got following messages on console:

Connecting to J-Link...
J-Link is connected.
Firmware: J-Link EDU Mini V1 compiled Aug 10 2021 11:19:22
Hardware: V1.00
S/N: XXXXXXXXXX
Feature(s): FlashBP, GDB
Checking target voltage...
Target voltage: 2.96 V
Listening on TCP/IP port 2331
Connecting to target...
ERROR: STM32: Connecting to CPU via connect under reset failed.
ERROR: Could not connect to target.
Target connection failed. GDBServer will be closed...Restoring target state and closing J-Link connection...
Shutting down...
Could not connect to target.
Please check power, connection and settings.

All the pin connections are done according to Segger application nore "Connecting J-Link to STM32-Discovery eval boards".

I also tried to connect using JLink command line utility (both on Windows and Linux) but it did not help.

Could you please suggest a solution or give some hints?

Thanks in advance.

Regards,
Abhijeet

Hello,

thank you for response and info.

I rechecked the connections but I still get following messages. I see that board is reset for a second but does not get connected. Is my JLink broken? I am using v7.52c of JLink Commander.

Please specify target interface:
J) JTAG (Default)
S) SWD
T) cJTAG
TIF>S
Specify target interface speed [kHz]. <Default>: 4000 kHz
Speed>
Device "STM32F429ZI" selected.



Connecting to target via SWD
InitTarget() start
Can not attach to CPU. Trying connect under reset.
Connecting to CPU via connect under reset failed.
InitTarget() end
InitTarget() start
Can not attach to CPU. Trying connect under reset.
Connecting to CPU via connect under reset failed.
InitTarget() end
InitTarget() start
Can not attach to CPU. Trying connect under reset.
Connecting to CPU via connect under reset failed.
InitTarget() end
InitTarget() start
Can not attach to CPU. Trying connect under reset.
Connecting to CPU via connect under reset failed.
InitTarget() end
Cannot connect to target.

Thanks & Regards,
Abhijeet

Hello,

I could connect to RPi Pico over SWD using JLink Edu Mini and also erase and flash it. Also debugging a program in Segger Embedded Studio worked. The problem was actually with loose connecting wires. Thanks for your suggestion regarding bad connections.

In similar way, I shall also be able to connect with STM32.

I am happy that my JLink is working.

Thanks & Regards,
Abhijeet
---

PS: Here is the log of JLink Commander. In case if anyone faces similar problem, these are the steps that are executed by JLink to connect with RPi Pico. Due to loose cable connections my JLink had stuck at ConfigTargetSettings in loop. After tightening the cable connections, connection was successfully established.

Type "connect" to establish a target connection, '?' for help
J-Link>connect
Please specify device / core. <Default>: RP2040_M0_0
Type '?' for selection dialog
Device>
Please specify target interface:
J) JTAG (Default)
S) SWD
T) cJTAG
TIF>S
Specify target interface speed [kHz]. <Default>: 4000 kHz
Speed>
Device "RP2040_M0_0" selected.

Connecting to target via SWD
ConfigTargetSettings() start
J-Link script: ConfigTargetSettings()
ConfigTargetSettings() end
Found SW-DP with ID 0x0BC12477
DPIDR: 0x0BC12477
Scanning AP map to find all available APs
AP[1]: Stopped AP scan as end of AP map has been reached
AP[0]: AHB-AP (IDR: 0x04770031)
Iterating through AP map to find AHB-AP to use
AP[0]: Core found
AP[0]: AHB-AP ROM base: 0xE00FF000
CPUID register: 0x410CC601. Implementer code: 0x41 (ARM)
Found Cortex-M0 r0p1, Little endian.
FPUnit: 4 code (BP) slots and 0 literal slots
CoreSight components:
ROMTbl[0] @ E00FF000
ROMTbl[0][0]: E000E000, CID: B105E00D, PID: 000BB008 SCS
ROMTbl[0][1]: E0001000, CID: B105E00D, PID: 000BB00A DWT
ROMTbl[0][2]: E0002000, CID: B105E00D, PID: 000BB00B FPB
Cortex-M0 identified.