The erase all function lets the debugger trigger an erase of non-volatile memory, user information configuration registers (UICR), secure information configuration region (SICR), RAM, all peripheral settings, and also temporarily removes the access port protection.
To trigger an erase all function, follow the sequence in the following flowchart. After the sequence has completed, the access port protection is removed until the next pin reset, power-on reset, brownout reset, or watchdog timer reset.
Erase all protection
It is possible to prevent the debugger from performing an erase all operation by using either the TAMPC TAMPC.PROTECT.ERASEPROTECT register, or the UICR.ERASEPROTECT register followed by a device reset.
Once this has been configured, the CTRL-AP ERASEALL operation is disabled.
The register ERASEPROTECT.STATUS holds the status for erase protection.