This module introduces Tarmac trace from Fast Models, and uses that to walk through everything a Cortex-M3 device would do if used with CMSIS code from Reset to the main() function, to triggering an interrupt using the NVIC. Although the module is related to a Cortex-M3 device, the details presented also apply to any Armv7-M / Armv8-M device, acting as a recap of all the content covered in this M-profile course.