Debug interface becomes inaccessible for s32k

[SanthoshP]

Dear NXP Support Team,

I am working on an application using the NXP S32K311 microcontroller, and I’ve encountered an issue where the debug interface becomes inaccessible and OSDA light goes to "red" after flashing my application code.

In my current pin configuration, I have assigned PTA3 as the SPI SCK line. After programming the firmware, I am no longer able to connect to the device via OpenSDA or J-Link — it appears that the SWD debug interface is disabled or overridden. I believe this may be due to PTA3 being used as the default SWD_DIO pin. (which I don't know while configuring)

Give me Official method for unlocking or mass erasing the MCU if debug access is lost? or any other solution for this issue.

Thank you for your support. Please let me know if you require any additional information.

Best regards,
Santhosh P

[SanthoshP]

Hi @VaneB

LED D8 not stays ON continuously. Actually the main issue is that MCU is not getting powered up. I have checked the power line from PMIC (FS23), the input for PMIC is 12v but the output from the PMIC is 0v (Both P5V0 & P3V3). I have checked the VDD pin from MCU. It also stays in 0v. I tried connecting external debugger also. Still MCU is not powered up. Do I need to connect/disconnect an jumpers? Could You please guide me ASAP?

[VaneB]

Hi @SanthoshP 

Did you notice any change in the temperature of the FS23? If possible, could you measure the input current to the FS23?

Additionally, could you clarify where exactly you are measuring the output voltage?

[SanthoshP]

Hi, I have analysed further, in my controller there is no default configuration for debugger SWD_DIO (Debug Data Pin). one more thing, the OSDA light in red colour and while resetting manually there is no LED blinking, I suspect power to MCU is off. I need clarity on this.

[VaneB]

Hi @SanthoshP 

Just to clarify, PTA3 is not a JTAG or SWD pin, so its configuration should not interfere with the debugger connection.

Could you confirm whether LED D8 stays ON continuously? If it does, that indicates that the S32K311 MCU is stuck in a RESET state.

Also, when you connect the J-Link to the J40 (JTAG connector) and try to flash the MCU, do you get any error messages? If so, please share it.

Lastly, you mentioned that you are unable to program the MCU using either the onboard debugger or an external one, which suggests the problem might not be with the debugger itself. To help narrow things down, could you tell me more about the last project you successfully flashed to the MCU? If possible, please share the project.

BR, VaneB