6.4.5 Sequence Number Fuse Check

The Boot ROM reads the Sequence Number (SEQNUM) fuse in the Boot Configuration (BOOTCFG) memory section automatically upon any type of reset to determine the preferred boot configuration:

1. When BOOTCFG.SEQNUM is not 0xFFFFFFFF, the Boot ROM copies the contents of the BOOTCFG fuses to the respective peripherals registers.
2. When BOOTCFG.SEQNUM reads 0xFFFFFFFF, the device is booted using the factory defaults of the peripheral registers, and no pin is asserted for the Boot Failure Signal.

When the value of this fuse is not all-F, it can be used by the bootloader or application for version tracking, as a time stamp, or for similar purposes.