How true.

This is the permanent thief-guard game. The only question is, whether it's wort. If the cost of "code recovery" is higher than the gain from having it, nobody will do it. Search the net - you might find out how much is a standard lockbit protection on standard mcus worth in $s...

The trouble is that many of the standard mcus'lock scheme appears to be easily overcomable by non-invasive methods - applying non-standard electric signals and heat and light... And that's cheap.

Better protection can be achieved only by a combination of methods and those methods should use a variety of principles.



On no; this protection is worth maybe 10 minutes of work (how much would you charge for this - $10?); somebody who is able overcome the lockbits would certainly repair a torn-off pin easily. So it is not even worth doing it - it would repel somebody who would only try to put the chip into a standard device programmer, but that one would be equally deterred by the standard lockbit protection.

But a mechanical protection is not a bad idea as it has possibly less impact on the electrical performance of the circuit. Maybe a hole carefully drilled in the vicinity of the centre of package, so that it cuts the bonding wire of the required port pin, could be used, well cleaned and filled with resin - that would be certainly more complicated to reconnect a bonding wire of 20um diameter than the wireframe.

Jan Waclawek