Re: [Amforth-devel] .s on 1284p

[pito <pi...@vo...>]

Marcin, MY BIG THANKS!!
I simply thought the RAM ends at 0x4000.. 
So 0x40af = 16559 what is aproximately the magic number 16557 !!!

Thanks again and sorry for my spaming the list.. Good night, Pito.

----- PŮVODNÍ ZPRÁVA -----
Od: "Marcin Cieslak" <sa...@sa...>
Komu: "pito" <pi...@vo...>
Předmět: Re: [Amforth-devel] .s on 1284p
Datum: 29.8.2010 - 2:16:44

> On Sun, 29 Aug 2010, pito wrote:
> 
> > Marcin, when I do .s I see an address higher
> > then 16383 (16557). So
> > > it is an indication for me something must be
> > wrong there. Matthias
> > > sent the .s definition, from what I can see is
> > he prints out the
> > > address (of RAM - I do assume - when talking
> > data stack), and as I
> > > have shown the number is 16557.. So outside the
> > RAM space. Maybe I
> > > am mistaken.. Just explain to me plz.. Assembly
> > listing of what,
> > > please? P.
> 
> Please see m1264Pdef.inc file in your AVRASM
> directory:
> 
> ---8<------------------------------
> .equ    SRAM_START      = 0x0100
> .equ    SRAM_SIZE       = 16384
> .equ    RAMEND  = 0x40ff
> .equ    XRAMEND = 0x0000
> ---8<------------------------------
> 
> RAM begins at $0100 and ends at $40ff.
> 
> So you have in your listing:
> 
> 00002a ff 40         .dw rstackstart  ; USER_RP^M
> 00002c af 40         .dw stackstart   ; USER_SP0^M
> 00002e af 40         .dw stackstart   ; USER_SP^M
> 
> Your return stack starts at $40ff and grows down 
> and your data stack starts at $40af and grows
> down.
> 
> Most ATmegas have stack at $0100, but some AVR
> CPUs have it at $0040, $0060 or $0200.
> 
> My ATmega164P has RAM from $0100 until $08ff,
> so my rstack starts at $08ff and my data stack
> grows down from $08af.
> 
> Hope it helps!
> 
> --Marcin