As I understand it the USN is a 128-bit number easily accessible, however for my purposes 128 bits is just a tad of an overkill, 32 would be about right.
Does anyone know exactly how this number is generated? If it’s truly random I can use any of the 32-bit words. If it’s an incrementing number generated in the factory I can use the least significant word as it won’t roll over in my lifetime.
Rob
Maybe it’s easiest if you don’t assume anything about the number and do some hash function 128 bits → 32 bits, even as simple as XORing the four words together.
Yep I will probably do something like that. I don’t have any chips yet so I can wait until I read some values and make a judgment based on what I see. If I get numbers like 00000000014ef1d3e… I can probably assume incrementing numbers. However if all words have data then maybe they are random.
I’m new to LPCs and finding the data a bit sparse, maybe I just don’t know where to look but I think AVR data sheets are more informative and there’s more code examples around. Still the 122x is a better choice for my app so I’ll struggle on 
I don’t suppose there’s an equivalent forum to AVRfreaks by any chance?
Rob
Closest thing is [http://knowledgebase.nxp.com/lpcxpresso.php](http://knowledgebase.nxp.com/lpcxpresso.php)graynomad:
…I don’t suppose there’s an equivalent forum to AVRfreaks by any chance?
Rob
Thanks, I’ll check it out.
Rob