On Sat, 10 Mar 2007, David VanHorn wrote:

>> What does the hardware stack depth have to do with C?  C does not
>> mysteriously consume hardware stack levels.
>
> Nothing "mysterious" about it, but C pushes a lot of things onto the stack
> in function calls and ISRs.

A C function call or ISR uses one level of the hardware stack, just
like assembly language.  I've never seen a PIC C compiler that used
the hardware stack for any additional storage purposes.

> In some of my ASM ISRs I don't push ANYTHING because it's not necessary.
> When you only have a three word hardware stack, I don't even think it's
> possible to use C, is it?

I've done a C application on the 10F200, which has a two-deep hardware
stack.  The application used zero of those stack levels, because my
code contained no function calls, and the 10F200 doesn't have
interrupts.

--
John W. Temples, III
-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist