If you're accessing any kind of I/O register or special memory, obviously you need to know the rules of engagement for the particular kind. If you don't, then

If you're accessing any kind of I/O register or special memory, obviously you need to know the rules of engagement for the particular kind. If you don't, then you're just going to be making the same mistake in a less obvious guise. Like writing *v=*v+1 instead of *v++.