I think this is what BigWumpus meant. But the tolerances are a bit tighter than the 0.3 and 0.7 times VDD. Catches more hackers. And still leaves room for 5% (or worse) resistors.
And, it's better to take a Reading when the system is Initialized, and use an even tighter tolerance from that reference point to determine if a TAMPER has occured.
<br>
Bookmarks