S32K3 cannot be connected after downloading SW with Mismatch MCU clock settings

[StephenY]

As the title mentioned, after downloading SW with mismatch MCU clock settings. the MCU cannot be connected by debugger anymore:

- reset the MCU not working;

- the App core seems in a state not running, or just run for a very short time.

what is the cause of the behavior?

and how to bring the MCU to normal state, so can be used flash New SW?

[Julián_AragónM]

Hi @StephenY,

Are you able to attach to target? 

Could you show what is the error shown when trying to connect? Also, please share which clock configuration was uploaded before this issue occurred.

Lastly, is this an evaluation board? Or custom implementation? Are you able to connect to any other boards?

If you are using JTAG, you can try to physically lower bReset and erase the flash so that the clocks will not be reconfigured anymore as in this community post: Solved: failed to power up dap after program s32k312 with pll0 equal 240M - NXP Community.

Best regards,
Julián

[StephenY]

Are you able to attach to target?  No, not able to attach.

Could you show what is the error shown when trying to connect? 

The snapshot shows below, with SWD type:

Lastly, is this an evaluation board? Or custom implementation? Are you able to connect to any other boards?

It is a custom implementation. and Yes, able to connect to other boards.

And I tried the steps from the attached link. failed, I am not sure whether the wire connection with JTAG from my side not well or some other causes.

[StephenY]

Hi, @Julián_AragónM 

  I double checked the wire connection, and the tried the failed target, the error shows below:

- The CPU could not be halted.

Do you have further clue about this issue?

Best Regards

[Julián_AragónM]

Hi @StephenY,

Have you tried the solution in the community post shared before? 

You can either pull the reset pin to low physically shorting it to GND, or you can use these commands:

r0
erase

It will ask you to establish the connection while the MCU is in reset (r0).

As the post says, I cannot reproduce the issue even when wrongly configuring the clocks. You may also try to use the J Flash tool from Segger and try to erase and verify the chip. 

Best regards,
Julián