Each EM250 and EM260 is programmed by Ember with one of Ember’s IEEE EUI64 addresses (also known as Long ID and MAC).This is programmed into the manufacturing section of the chip’s flash and can not be erased or altered.
Customers can use the Ember pre-programmed EUI64 for their products, or they may also choose to use their own block of IEEE address, in which case they will need to program their EUI64 during product manufacturing. This does not overwrite the Ember EUI64 but it does configure the chip to use the one supplied during manufacturing.
The procedure for programming a custom EUI64 can be found in App Note “Bringing up custom devices – 120-5031”
EM35xx chips can be programmed with a custom EUI token as well. Please see the updated AN710: Bringing Up Custom Devices for the Ember® EM35XX SOC or NCP Platform app note for doing so.
EFR32 chips also have the capability of having custom EUIs. The token can be set using the command line in the latest version of Simplicity Commander. The token and procedure for EFR32 are described in App Note AN961: Bringing Up Custom Nodes for the Mighty Gecko and Flex Gecko Families.
Note that when assigning Custom EUI64 programmatically, a reset is required to apply the correct EUI64 to all stack values and messages.