My currently biggest issue with my setup is, that to get some
information from a register, I have to print its content with gdb (from
inside Emacs), put that into the mate-calculator to find which bits are
set and which are not and finally open up the datasheet of the CPU and
look up the meaning of each bit.
I don't have a ready-made solution for you, but note that GDB
is scriptable. If you look at Emacs's src/.gdbinit file
(http://git.savannah.gnu.org/cgit/emacs.git/tree/src/.gdbinit)
you can see what we do to help ourselves debug Emacs's C code.
Note how you can use C-like operations in it, so you could code up some
.gdbinit file for yourself where you write some handy commands that
print the state of your devices's registers in a meaningful manner.
Note that this is a "GDB-only" solution (the only Emacs part of it is
that you got the info in an Emacs discussion group, and that the sample
file provided came from Emacs's source code).
Stefan