gnupic: Any way to address the stack?
Subject:
Any way to address the stack?
From:
David McNab ####@####.####
Date:
8 Nov 2004 04:16:43 +0000
Message-Id: <418EF321.20903@rebirthing.co.nz>
Hi,
Is there any way to access the hardware return stack on PIC 16F873A?
In other words, to get the value of the current stack pointer, as well
as read (and possibly also write) the contents of the 8 stack levels
themselves?
I ask, because I'm looking at ways of implementing a software
call/return stack, and thus eliminating the ceiling of 8 call levels.
As it is, a software call/return stack would be inefficient, because it
would require something like:
movlw low(return_address)
movwf return_address_low
movlw high(return_address)
goto sw_stack_call
return_address
...
This comes to 4 words per call, which will rapidly bloat out the
application.
If there were a way to 'hack' the return stack, I could cut this to one
word per call.
Just asking, on the possibility that one of the 'unimplemented' FSRs (or
some other hack) might let me access the stack.
Thoughts?
--
Cheers
David
