Datasheet

Figure 22-4. EEPROM and Boot Loader Allocation
Related Links
10.2 Physical Memory Map
22.6.3 Region Lock Bits
The NVM block is grouped into 16 equally sized regions. The region size is dependent on the Flash
memory size, and is given in the table below. Each region has a dedicated lock bit preventing writing and
erasing pages in the region. After production, all regions will be unlocked.
Table 22-1. Region Size
Memory Size [KB] Region Size [KB]
256 16
128 8
64 4
32 2
To lock or unlock a region, the Lock Region and Unlock Region commands are provided. Writing one of
these commands will temporarily lock/unlock the region containing the address loaded in the ADDR
register. ADDR can be written by software, or the automatically loaded value from a write operation can
be used. The new setting will stay in effect until the next Reset, or until the setting is changed again using
SAM D21 Family
NVMCTRL – Nonvolatile Memory Controller
© 2018 Microchip Technology Inc.
Datasheet Complete
DS40001882D-page 387