> The TABLPTR is 16-bits wide.  So write 80 to TBLPTRH and 00 to TBLPTRL.
> Then execute a TABLRD instruction.  The trick here is that the data read
> is not immediately passed to the file register of your choice.  It passes
> through a (not mapped in data space) latch first.

What's the best way of doing a context save/restore if an ISR needs to use
TABLRD [in ROM-only systems] or else both TABLRD and TABLWT [in systems with
external RAM]?

According to what others have posted, the 17Cxx uses seperate latches for
the table-read and table-write instructions.  Does this mean that the only
way to put something into the table-read latches is to read it from memory?
If so, is there any good way to accomplish this other than [in a RAM-based
system] doing something like:

SAVE:
        save a copy of the current table pointer
        point to a spare spot in RAM
        save the contents of the table-read latches
        do a table-write (to record the contents of the write latches)

RESTORE:
        point to another spare spot in RAM
        put the saved table-read latch contents into the write latches
        do a table write, followed by a table read
        put the saved table-write latch contents into the write latches

That seems ickly.  Is there a better way?