[En-Nut-Discussion] Recommended compiler?

Austin Schutz tex at off.org
Tue Oct 8 06:58:55 CEST 2002


On Mon, Oct 07, 2002 at 11:31:55AM +0200, Harald Kipp wrote:
> Austin,
> 
> > > The 8019AS has its own internal 16 bit address decoder.
> > > So all ATmega address lines are connected and the
> > > controller occupies address space 0x8300 to 0x831F only.
> > >
> >
> >         Other implementations I've seen only have the first four addresses
> >lines connected. If you can't access the buffer memory, why connect the
> >other pins? I'm not trying to be difficult, I'm just trying to understand.
> >I've been programming for a bit, but this low level stuff is a little new. :-)
> 
> :-) If you're using 4 lines only, the RTL8019 registers
> will appear in the whole address space. Either the other
> implementation didn't use any other addresses or the
> Controller is connected to port pins, not address lines.
> 

	On one implementation it looks like they tied A15 to AEN, which
is basically equivalent. Looks like on another (picoweb) they just use
the lower 4 of port2 and don't use any external ram.


> In any case you have to use the Realtek data sheet.
> The 8390 (and 83905) can only be used as a second
> source document. It much better explains the NE2000
> buffering, but that's it. Specially on error recovery
> you can't trust any of these datasheets, but use
> a good oscilloscope or logic analyzer with trial and
> error programms.
> 

	Ok, that's good advice, thanks.

	I had an idea for bank switching, btw. It looked like in the mail
archive folks were asking about it a bit back (before I joined the list).
Are ideas still welcome? If so, what format would make sense? It would
seem a bit awkward to post schematics in ascii.

	Austin



More information about the En-Nut-Discussion mailing list