On NXP Kinetis KV1x, Kinetis KV3x, and Kinetis K8x devices, Flash Access Controls (FAC) (a software IP protection method for execute-only access) can be defeated by leveraging a load instruction inside the execute-only region to expose the protected code into a CPU register.
https://www.usenix.org/system/files/woot19-paper_schink.pdf
https://www.usenix.org/conference/woot19/presentation/schink