The SAM E70/S70/V70/V71 embeds 1 Kbytes of backup SRAM located at 0x4007 4000.
The backup SRAM is accessible in 32-bit words only. Byte or half-word accesses are not supported.
The backup SRAM is supplied by VDDCORE in Normal mode.
In Backup mode, the backup SRAM supply is automatically switched to VDDIO through the backup SRAM power switch when VDDCORE falls. For more details, see the “Backup SRAM Power Switch” section.