Small Device C Compiler suite

Hello Franz,

Don't know too much about the ds390 and nothing about the ds5250, but I can recommend to 
have a look at their datasheets. Esp. the instruction sets. If they are equal or the ds5250 can at 
least do everything the ds390 can do, you can probably use the ds390 port. In other words if the 
cores are compatible, you're fine, I guess.

The ds390 port uses/accepts different memory models like flat24 and makes use of the dual data 
pointers.

I do recommend to create your own header file for the sfr's. And we welcome you to upload it in 
the patch area if you like.

> Greetings,
> 
> I'm working with a DS5250  (Similar to DS390), and I'm very new to SDCC.
> A few issues are puzzling me:
>   a.. Should I still use the "-mds390" directive when compiling my code, and just change the DS390 header file to include my sfr's?  What exactly does the compiler do if I specify "-mds390".
>   b.. Can/Should I create my own processor directive?
> Any advice would be really welcome - I'm totally in the doldrums here!
> Franz