When you decide to copy protect the firmware on your MCU, how effective are efforts such as setting a lock bit or enabling chip erase modes?
Sergei P. Skorobogatov’s article provides an overview of the methods he’s tried against MCUs from various manufacturers. He outlines both invasive and non-invasive techniques such as chip depackaging, microprobing and fault generation.
This document is somewhat historical in nature, covering techniques developed between 1996-2000. Nevertheless it is regarded as one of the foundational works on this aspect of hardware hacking.
Sergei has updated this information with his PhD thesis from 2004.