Just designing a product for EMC testing ATM and came across this...
"A bus access to a non-existent address returns the data #ff, provided there is a passive pullup on the bus. Nothing can be done about this. Hovever, un-programmed ROM also returns #FF and this can be changed. A good approach is to convert all unused #FF locations to the processor's one-byte NOP instruction. The last few locations in ROM can be programmed with a JMP RESET."
from "EMC for Product Designers" Tim Williams
Basically the idea is if the PC goes crazy it will hit the NOPs and reset the processor.
Is this worth implementing?
Is there an easy way to implement it in C?