Securing flash of MCU-MKV46F256xxx16

[reshma-nexgen]

Hi,

I'm using MKV46F256xxx16 in my project and I want to secure the MCU. After I secure the MCU, the MCU code is not working.

I have changed the flash configuration bit in startup_mkv46f16.c. as follows:

Here “F8” represents the following configurations:

• KEYEN : 11 Backdoor key access disabled
• MEEN: 11 Mass erase is enabled
• FSLACC: 10 NXP factory access denied
• SEC: 00 MCU security status is secure.

I have also selected "allow security" in JLink Debugger section.

After I secure the MCU the code is not working. Attached is the test program. In here, PORTB pin 2 is toggles at ~7KHz. After securing the MCU, this toggling is not observed even after power recycle.

Let me know if there is a way to solve this issue.

Regards,

Reshma.

[PabloAvalos]

Hi @reshma-nexgen 

Thanks a lot for reaching our technical support and thanks for your patience.

Regarding your issue, you mean that before securing your mcu, you were able to see that pin toggling @7 KHz ? Confirming this, it is supposed that for securing the mcu you only need to modify the SEC register, depending on the security you want. You may refer to this application note for reference: https://www.nxp.com/docs/en/application-note/AN4507.pdf 

Hope the information was helpful, please let me know if you have some more questions or comments.

Sincerely,
Pablo Avalos.