Gerhard Fiedler wrote:
> How do you deal with that (when/if you have to)?

It hasn't come up.  Why do you need to?

I have occasionally needed to verify that a PIC contained the information in
a specific HEX file.  For that I use my PIC_PROG program with the -V command
line option.  It looks up the particulars of the PIC in a data file.  This
information includes which config bits are relevant and which ones are not.
Mismatches in the irrelevant bits are ignored.

> Can I set the unused bits to 0 in the
> original hex file?

You can set them to anything you want in the source code.

> If that's not an option, does that mean that normal hex file
> comparison tools are not really that useful in this scenario?

Right.

> Any tricks or solutions?

Yes:

1 - Don't do that.  A legitimate reason for needing to do that hasn't come
up yet in all the years I've been programming PICs.

2 - You can use the facilities in my PICPRG library to get used/unused bit
information for any of the PICs I currently support.  The data file format
is documented, so you can add information for PICs not in there.  Once you
have this information, you write a program that reads both HEX files into
memory arrays, then compares the result taking the config bit masks into
account.  The PIC_PROG program contains code to read a HEX file into several
data arrays.  There is more too this than might be immediately apparent, so
you are probably better off using that code somehow.


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