How to change the UCB content

[Jarvan]

accroding to the AURIXTC3xx_um, before changing the UCB , it should confirm the ORIG and COPY UCB confirmation codes are CONFIRMED. However, the UCB cannot be changed if it is CONFIRMED.  Need i set the confirmation to CONFIRMED?

[Karishma_S]

Hi @Jarvan,

In a new device, the UCB_ORIG/COPY comes with UNLOCKED confirmation state and it is safe to write UCB_COPY in the unlocked state with the password and then UCB_ORIG in the unlocked state with the same password. After this both can be compared to be the same and then set to CONFIRMED state(UCB_COPY and then UCB_ORIG).

And hence, the 1st step of re-programming dual UCBs is to confirm if the UCB_ORIG/COPY are in CONFIRMED states. This is done to avoid a scenario of UCB_ORIG being in ERRORED state and UCB_COPY being in UNLOCKED state. This is also mentioned in user manual (see below image).

In addition, you can change the contents of the UCBs in confirmed state by providing the right password to the disable protection command sequence as mentioned in the next steps of 'Dual Password UCB ORIG and COPY Re-programming' .

For more details on disable protection command sequence, please refer the section 6.5.2.2.3 of user manual.

Best Regards

[Jarvan]

Thanks for your apply.  As mentioned above,  will the chip be locked if UCB_ORIG  in ERRORED state and UCB_COPY in UNLOCKED state?  Another question is that some UCB without password, such as UCB_HSMCOTP0_ORIG, how to change the UCB's contents when it is CONFIRMED.

[Karishma_S · Accepted solution]

Hi @Jarvan,

As mentioned above,  will the chip be locked if UCB_ORIG  in ERRORED state and UCB_COPY in UNLOCKED state?
-> No, the  chip does not lock if UCB_ORIG is in ERRORED state and UCB_COPY is in UNLOCKED state. But, all bus masters can access the contents and password of the UCB in this scenario. 

Another question is that some UCB without password, such as UCB_HSMCOTP0_ORIG, how to change the UCB's contents when it is CONFIRMED.
->  If the HSMCOTP0 configuration set is in CONFIRMED state then only the HSM is allowed to program the HSMCOTP1 configuration set. If HSMCOTP1 is also in CONFIRMED state then the complete HSMCOTP configuration set is OTP protected.  Please refer the section 6.5.4.3.12 of user manual for more details.
As this UCB is used for One Time Programmable (OTP) protection for the dedicated HSM flash sectors, it is not logical to change the configuration after CONFIRMED state.

Best Regards