This is kind of getting away from the original theme of this thread, which was "how do I make my C programs fast and small". That led to the discussion of the different access speeds for the different memory areas, and then to some guidelines for chosing the best memory area for any given variable.

Code memory, of course, has the nasty feature that your program can't write to it, so it doesn't really matter to the present discussion how fast it is or isn't.

-- Russ