I am using the PIC18LF4320 and the C18 compiler. I am running very close
to the end of my GPR RAM and sometimes cannot fit due to RAM space
issues(linker errors). Thus, I have been "trying" to learn about how the
memory is allocated looking at my .map file, the linker script and the
user manual and have four questions about how I might use some of what
looks like unused memory. I have no external memory. The 1st 128 bytes
is "access RAM"(000-07F). The next group seems to be for my
use(080-0FF). Next, the linker script has allocated 256 bytes for the
stack (from (100-1ff). So that I understand is off limits - right? The
SFRs are using up the last 128B of RAM(F80-FFF). I hope you are
following me here - it is hard without a picture of the memory map. This
leads me to the following assumption/questions:

1)All of the variables I have created in code are stuck at the
128B(080-0FF) between the end of ACCESS RAM and the beginning of my
STACK. If my code required more than 128 I am out of luck and must
reduce my number of variables/storage right?

2) Looking at my memory map (.map) file the "stuff" in the ACCESS RAM is
only using 000 - 014h - leaving a bunch of unused space in ACCESS RAM
from 014h to 080h. Can I use a PRAGMA and force some of my variables to
make use of this space?

3) The 1st page of the data sheet does say I have 512B of RAM available
(which seems to add up if it is 000-1FF; however, I was wandering if the
128 bytes in BANK15 (F00-F7F)(the SFRs are using the upper 128B) exist
and is useable? Or is that wishful thinking?

4)Is there any way to learn how much STACK I really need - maybe I could
define it smaller than the default 256B, which uses up 1/2 of my
available memory?

Thanks for any help all,
Shawn

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