AVR-Chat

At 10:18 AM 12/12/2003 +1100, Rob Storey wrote:
>
> > A very common problem is where one routine messes with another's variables.
> > Either by direct reference, or indexed as My_Ram+5 accidentally stepping on
> > Your_Ram
>The trouble here is the concept of "ownership" of the variables (This is
>clearly defined and controlled in high level OOP languages, but not in
>assembler). The same problem arises in detecting corruption of variables
>by interrupt handlers - it alters a register, but should the ISR have
>preserved the register, or does it "own" the register and therefore the
>action is legitimate?

That's for me to decide, but if routine X uses Thing_A by name,  and 
routine Y uses the same address in ram by Thing_D+14, then I would suspect 
a collision.
Just having an absolute, and automated search for all refs to a given sram 
or register var would be a big help.
Atmel seems to not get that a very frequent debug problem is "who hosed my 
data".
Breakpoint on write to X isn't in the cards, apparently.


>Don't know, but I'd be looking for one! 'twas a general comment that
>comtemplating techniques like that is a dead giveaway that you've
>outgrown your hardware capacity.

In this case, it was a tour de force :)