Why is this UID value set to 0 in the example code?

[InhyeokHwang]

Hi NXP teams

I saw that UID is a unique value for each microcontrollers and it's set on the manufacturing process.

But in the process of the loadkey in the cse example code (cse_keyconfig_mpc5777c), I can see that uid is defined with value 0. 

Why is this so?

 

[lukaszadrapa · Accepted solution]

Hi @InhyeokHwang 

this is called wildcard UID and it is given by SHE specification.

All keys can be initially loaded using wildcard UID 0. Each key (except RAM key) have WILDCARD attribute. If you set this bit while loading a key, it's not possible to use wildcard UID anymore for this key. If you keep it '0', wildcard UID can be used also for updates of that key.

Regards,

Lukas