[En-Nut-Discussion] Ethernut 2 Xmem & Banked Memory

[Dusan Ferbas]

Hi,

my suggestion is just to change NUTXMEM_SIZE value.
We are using it this way with Charon2, which also uses XILINX for 
address decoding and memory banking.

I think this will work on Ethernut2 too. My question was, if 8kB 
mapped for planned for custom extensions, can be used as a heap RAM too.
I know, that this will require CPLD reprogramming, but I do not know 
how complicated this is and how much effort it can take ?

 >nut\include\cfg\memory.h
 >NUTXMEM_START 0x1100
 >
 >nut\arch\avr\os\nutinit.c
 >NUTMEM_END = NUTXMEM_START  + NUTXMEM_SIZE -1U
 >
 >NUTMEM_END is later used in NutHeapAdd
 >NUTXMEM_START is provided during configuration

========================
 >From: Dusan Ferbas <dferbas at etech.cz>
 >Date: Thu, 07 Feb 2008 15:41:23 +0100
 >Subject: [En-Nut-Discussion] Ethernut2 - more RAM
 >
 >is it possible to change CPLD program to extend directly accessible
 >RAM e.g. to 32+16 + 8kB (unused areas for custom extensions - see
 >http://www.ethernut.de/en/hardware/enut2/memmap.html).
 >A dream solution will be to offer some internal CPLD "register" that
 >will serve as memory configurator.(like bank select register).

========================
 >From: "Henrik Maier" <hmlists at focus-sw.com>
 >
 >I think what Steve wants to achieve is just to have one bank enabled all the
 >time right from start-up so his main memory is made up from 32 K standard
 >memory + 16 K banked area = total of 48 K area. He is not interested in
 >swapping banks around or accessing memory beyond 48 K.
 >
 >Basically using the Ethernut 2 in a configuration where the XRAM is 48K in
 >total instead of 32K.
 >
 >Does anybody know if this is possible and if yes how can it be setup with
 >Imagecraft?


Dusan