topic Re: Cannot connect to taget with RESET (pin 15) high, but shoud be low in Hardware

Cannot connect to taget with RESET (pin 15) high, but shoud be low

TnseoRnr — Thu, 11 Jul 2024 07:27:22 GMT

We have a custom board that is very similar to the EVB. I was using it well, but suddenly a problem arose for no reason. I am using Jlink.

I am trying to connect using JFlash, MCUXpresso IDE, JLINK.exe (command window?), but it fails.

On multiple identical boards, only certain boards exhibit this symptom.

As expected, I am wondering if a hardware issue has occurred in the IC or MCU, or if protection such as protection mode is in progress. Below is the message that occurs when attempting a JLINK connection.

*JLINK.exe

Connecting to target via JTAG
TotalIRLen = ?, IRPrint = 0x..000000000000000000000000
Failed to identify target. Resetting via Reset pin and trying again.
RESET (pin 15) high, but should be low. Please check target hardware.
TotalIRLen = ?, IRPrint = 0x..000000000000000000000000
TotalIRLen = ?, IRPrint = 0x..000000000000000000000000
Failed to identify target. Resetting via Reset pin and trying again.
RESET (pin 15) high, but should be low. Please check target hardware.
TotalIRLen = ?, IRPrint = 0x..000000000000000000000000
Cannot connect to target.

Even on boards where JLINK connection is difficult, the last downloaded firmware is operating normally.

The key is that I used the firmware update normally and then it became unusable. Other identical boards are still being used while updating their firmware normally.

The MCU is using MIMXRT1176XXXA_M7 and referenced MIMXRT1170-EVK. The JTAG-related circuit is used almost similarly to the EVB board.

What can I check?

Re: Cannot connect to taget with RESET (pin 15) high, but shoud be low

kerryzhou — Mon, 15 Jul 2024 03:14:37 GMT

Hi @TnseoRnr ,

Thank you for your interest in the NXP MIMXRT product, I would like to provide service for you.

Do you connect the JTAG_MOD pin to the ground or not?

Do you also try the SWD interface, whether that works or not?

You can use the JLINK commander to connect, and share the whole log.

From your test result, should still related to your board hardware, as some board works with the same schematic, maybe you also need to check the power on sequence, whether the power is correct or not.

Best Regards,

Kerry

Re: Cannot connect to taget with RESET (pin 15) high, but shoud be low

TnseoRnr — Wed, 17 Jul 2024 00:37:39 GMT

Yes, it is grounded.

Again, I have the same model in good use.

My guess is that it is protected or the MCU is damaged, but the previously downloaded firmware operates normally even in the MCU where JTAG is not connected.

Is there anything I can check?

Re: Cannot connect to taget with RESET (pin 15) high, but shoud be low

kerryzhou — Wed, 17 Jul 2024 08:43:26 GMT

Hi @TnseoRnr ,

You mean, the same board schematic, more boards, some board is working, just some board is not working, right?

If this situation, use the JILNK commander to check your chip, whether can find the ARM core or not, if can't find the ARM core, it means your hardware solder may have issues.

I mean, something like this:

Best Regards,

Kerry

Re: Cannot connect to taget with RESET (pin 15) high, but shoud be low

TnseoRnr — Mon, 22 Jul 2024 05:20:14 GMT

fail1fail2

It's the same whether it's SWD or JTAG.

Is there another method I can consider?

Re: Cannot connect to taget with RESET (pin 15) high, but shoud be low

kerryzhou — Tue, 23 Jul 2024 07:02:58 GMT

Hi @TnseoRnr ，

Thanks for your updated information.

JLINK can't find your ARM core, it means your hardware still have issues, you need to check your customer hardware situation, the power on sequence, etc.

Please double check your hardware at first, thanks.

Best Regards,

Kerry