I recommend this CCC presentation by an AMD engineer: <a href="https:&#x2F;&#x2F;media.ccc.de&#x2F;v&#x2F;32c3-7171-when_hardware_must_just_work" rel="nofollow">https:&#x2F;&#x2F;media.ccc.de&#x2F;v&#x2F;32c3-7171-when_hardware_must_just_wor...</a><p>The bottom line is that as a last resort debugging method, all modern chips can do scan dumps, which means reading out the state of every flip-flop on the chip. Obviously I have no idea whether that was needed by Intel to find this bug. It&#x27;s possible that a higher-level emulation or some other technique was sufficient. But when all else fails, you can still do scan dumps.