5.2.3 SecureBoot Command

The SecureBoot command provides support for secure boot of an external MCU or MPU. The general approach is that the boot code within the system will use the ATECC608B-TFLXTLS to assist in validating the application code that is to be subsequently executed. The ATECC608B-TFLXTLS device has been configured to operate in the SecureBoot, Stored Digest mode. The digest will be stored in Slot 7 and the public key required to verify the SecureBoot is stored in Slot 15. The device can optionally be configured to use the persistent latch. Depending on the option selected SecureBoot may or may not be tied to power-up. Please see Secure Boot Option

In lieu of a return code, a MAC can optionally be generated from a nonce written to TempKey, the IO protection secret and various other data, dependent upon the mode of the command, to prevent tampering with the wire between the host and the ATECC608B-TFLXTLS.