13.2 Arm TrustZone Technology for Armv8-M
Arm TrustZone for Cortex-M technology is an optional core extension, which enables the system and the software to be partitioned into Secure and Non-Secure domains.
Secure software can access both Secure and Non-Secure memories and resources,
while Non-Secure software can only access Non-Secure memories and resources.
If the TrustZone is implemented (SAM L11 devices), the system starts up in Secure state by default.
The security state of the processor can be either Secure or Non-Secure.
Important: For additional
information, refer to “TrustZone Technology for ARMv8-M Architecture”, which
is available on the Arm web site (www.arm.com).