NXP Semiconductors KL25 Series - Security Interactions with Debug

8.3.1 Security Interactions with Debug
When flash security is active the SWD port cannot access the memory resources of the
MCU.
Although most debug functions are disabled, the debugger can write to the Flash Mass
Erase in Progress bit to trigger a mass erase (Erase All Blocks) command. A mass erase
via the debugger is allowed even when some memory locations are protected.
When mass erase is disabled, mass erase via the debugger is blocked.
Security Interactions with other Modules
KL25 Sub-Family Reference Manual, Rev. 3, September 2012
150 Freescale Semiconductor, Inc.