How enable Trust Zone to run the trusted application in ARM Cortex M3.
TrustZone for Cortex-M was added in Armv8-M architecture. The processors you mention at Armv7-M. See the following links for more information:
https://www.arm.com/technologies/trustzone-for-cortex-m
https://developer.arm.com/Processors/TrustZone%20for%20Cortex-M
Regards, Ronan