9.3 Functional Description

The Boot ROM Code executes after every reset before control is handed to the application.

It performs a self-test including a VREG Monitor check that halts booting until the voltage range has been deemed valid, a CRC scan of the Boot ROM contents combined with various other integrity check mechanisms. Any error detected in the self-test or during the execution of the Boot ROM Code will trigger a Machine Check Reset.

If the CRCBOOT bit in the System Configuration 0 (FUSE.SYSCFG0) fuse is set, the Boot ROM will perform a CRC scan of the Boot Section in the Flash. Refer to the CRCSCAN - Cyclic Redundancy Check Memory Scan section in the data sheet for more details about CRC.