23 Mar
2006
23 Mar
'06
7:56 p.m.
I think that having a 'you can never write this' bios image would be useful. The power fail scenario is a concern.
Many flash parts support a hardware lock where you can set a split. Areas that have been hardware locked can only be reprogrammed via the right programming voltage which is normally much higher than Vcc.
-- Richard A. Smith