Re: [avr-gcc-list] Storing variables in external memory - suggestions

[Dave Hylands]

Hi Nayani,

Replying to the list this time as well.

On Sat, May 23, 2009 at 3:24 AM, Parthasaradhi Nayani
<address@hidden> wrote:
...snip...
> Hello David Kelly,
> I tried as you mentioned and seems to work fine. One more question is, how to 
> know the address ranges used by WinAVR? so one can use the unused ranges for 
> external EEPROM, FLASH etc. Thank you.

I'm not David Kelly, but I know the answer...

They're in the linker script.

The simplest way is to the following from the command line:

avr-gcc -mmcu=atmega8 -Wl,--verbose

Replace the atmega8 with the particular chip you're interested in.

The output of this will contain the following near the top:

MEMORY
{
 text      (rx)   : ORIGIN = 0, LENGTH = 8K
 data      (rw!x) : ORIGIN = 0x800060, LENGTH = 0xffa0
 eeprom    (rw!x) : ORIGIN = 0x810000, LENGTH = 64K
 fuse      (rw!x) : ORIGIN = 0x820000, LENGTH = 1K
 lock      (rw!x) : ORIGIN = 0x830000, LENGTH = 1K
 signature (rw!x) : ORIGIN = 0x840000, LENGTH = 1K
}

Those are the addresses used by the linker.

-- 
Dave Hylands
Shuswap, BC, Canada
http://www.DaveHylands.com/