FRDM-MX91 CPU lifecycle OEM_OPEN

[TheUncle]

Hello,
I recently got a FRDM-MX91 board to do some bare-metal experiment with the A55, just to discover that the CPU lifecycle is OEM_OPEN ("OO" in USB descriptor string), thus preventing unauthenticated debugging. This means, for example, that TRDC registers cannot be accessed and debugging hangs quite often.

Is there any specific reason why the CPU lifecycle on this development board (and I suppose also on FRDM-MX93) is not TEST/DEVELOPMENT (i.e., "BA" in USB descriptor string)?

To my knowledge, the only solution to this issue is to replace the CPU with a brand new one - or do I have other options?

Thank you in advance and best regards,
Stefano

[Harvey021]

Hello,

Before the LC for chip move forward to OEM_CLOSE from OEM_OPEN, it can be considered as TEST/DEVELOPMENT. If I don't misunderstand. 

Regards

Harvey

[TheUncle]

Seems not. In TEST/DEVELOPMENT debugging does not require authentication and all registers should be accessible (including TRDC), while in OEM_OPEN they are locked.

Regards,
Stefano

[Harvey021]

Authentication is not required, but release RDC is required, as only ele has permission at the beginning.

Regarding blank EVK, I've checked with the internal team that only OEM OPEN LC chips are provided.

Regards

Harvey

[TheUncle]

Just wondering if on the standard EVKs the chips are shipped as blank.

Thanks,
Stefano