MPC5646C CSE Questions

jinjingyang — Wed, 21 Sep 2016 15:59:05 GMT

Dear Sir,

Some questions on MPC5646C CSE.

1) Because Debug Authorization command need input using KDF (MASTER_EUC_KEY, DEBUG_KEY_C)

If MASTER_ECU_KEY is unknown, we have no way to erase the MCU's user keys?

2) Debug Authorization command will erase all user keys.

Does here user key include BOOT_MAC_KEY?

3) How can we identify a key slot is empty?

For a fresh part we need load key for the very first time.

Should we just use LOAD_KEY command directly and the error code will be returned if it's not empty?

Regards,

Jason Yang

Re: MPC5646C CSE Questions

petervlna — Thu, 13 Oct 2016 07:18:43 GMT

Hi,

Yes, If MASTER_ECU_KEY is unknown, you can not launch DEBUG_AUTH command to erase the user keys.
Yes DEBUG_AUTH command erases al user keys including BOOT_MAC_KEY 3. There is no way to identify it directly but you can use the negative approach to do the same. You may perform any operation using a key and returned error should tell you whether the slot had key or was empty.

Peter