Unable to connect to S32K144 on custom board via J-Link SWD — “Could not find core in Coresight setu

[sandeepgowda]

Hi everyone,

I’m working with a custom board using the S32K144 MCU and trying to debug it via SEGGER J-Link using SWD.

I’m running into this issue when connecting with JLink.exe (or via S32 Design Studio):

• J-Link detects the device and SWD-DP (ID 0x2BA01477).

• It reports that the device is secured and tries to unsecure (mass erase).

• However, it fails to halt the CPU and cannot read the CPUID register.

• “Attach to CPU failed. Executing connect under reset.” is repeated.

• Ultimately, it fails with “Could not find core in Coresight setup” and disconnects.

I have tried:

• Unsecuring the device (mass erase).

• Connect under reset option enabled in S32 Design Studio.

• Lowering SWD speed.

• Verifying that VTref = 3.3 V (target powered).

• Basic cable and connector checks.

Questions:

1. Could this be a reset line wiring or behavior issue? What’s the best way to verify/reset the board manually?

2. Any known quirks with S32K144 and J-Link SWD connection?

3. How can I confirm if SWDIO and SWDCLK signals are correctly connected on my custom board?

4. Are there recommended steps to debug this kind of “Could not find core in Coresight setup” error?

I’d appreciate any suggestions or troubleshooting tips. Thanks!

[Robin_Shen]

Hi

Please check the SWT interface: note the pull-down resistor added externally to the SWD_CLK pin.

If you are using the 9-Pin Cortex-M Adapter, please make sure that the RESET signal of the S32K144 is connected to the nRESET signal(pin 10) of the J-Link.

Then refer to the discussion in Unbricking S32K146: pull RESET low, then use the J-link commander and these commands to try to connect.

Best Regards,
Robin
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[srinivasaraomannem]

we have 10k pul up at TMS,TDI,TDO
10k pull down at TCLK
4k87 at reset