Hi

> If you describe what problem you think you are solving using this,
> it would be easier to tell.
Ok, on receipt of an RS232 command (a single character followed by optional
argument characters depending on the command), I want to 'goto' the unique
handling code for each command.  So I thought I'd have a table of command
characters :- db "abcde",0x00.  When I find a match, I use the offset of the
matching command as an index in to a 'jump table' using FSR/INDF.  The jump
table looks like this;
goto handler_a
goto handler_b
goto handler_c
goto handler_d
goto handler_e

The only problem is getting the "abcde", 0x00 inititialised data table set up.
Seems pointless having an idata section if I have to manually movlw, mvwf for
each value.

> The 628A can not directly read it's (own) Flash memory, so it
> have to be RETLW instructions. Havn't tried it. Then you probably
> have to "call" that "lookup table" and MOVWF your values into
> the RAM space (reserved but not initialized by the IDATA driective).
I got the ideas/opinions from MPASM/MPLINK docs, so I guess this doesn't
necessarily apply to 16F628A?

> Then you must already be using a LNK script !?
> Or havn't you done *any* (non-error) build yet ?
> And you don't have to "play" with it, just add the LNK
> file to your project, you must do that anyway, no matter
> the IDATA directive...
Yes indeed I have, and all works fine; I currently usepic16f628a.lnk, NOT
pic16f628a*i*.lnk - which I just found, just wondered what the difference was
and if it'd help with the initialised data.  I've been writing my code and
running it on the simulator for a few weeks now.

Just thought I'd post for any ideas/suggestions before my train journey home
tonight, where I'll get my next chance to do some PIC work.

> Yes. code calling your "lookup table". Just as usual. The IDATA
> directive just helps creating the RETLW instructions (I think ! ).
Forgive my ignorance, but how do I do this?  I did notice an idata_i (or
something like that) in the map file, and had a look with the program memory
window at the location in the map file - I see my data there, but not in the
actual file register (as expected).

Actually, I think I have just realised what you refer to: the linker converts
the idata stuff in to some RETLW <mydata> for each byte, and I need to 'call'
the relevant offset to get the value, is that right?  I'm still not sure how I
know what memory location to offset my 'call' from though.

Cheers,
Mark

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