[ECOS] ARM - RAM region at other address than 0

Grant Edwards grante@visi.com
Mon May 19 20:38:00 GMT 2003


On Mon, May 19, 2003 at 04:11:38PM -0400, Doyle, Patrick wrote:

> I glanced at the '5471 data manual and I don't see the
> "mechanism for swapping ROM and SDRAM at address 0" that I was
> expecting to see... Hmmm.... Perhaps you should ask TI about
> this.  eCos really likes to see interrupt vectors in RAM.

At one point I had a hacked version of vectors.S that worked
with ROM at 0.  It did the "double vector" thing (not very
pretty).  After tiring of the requirement to maintain my own
vectors.S, I finally swapped ROM/RAM -- life is easier that
way.

If the 5471 doesn't have some sort of software-controlled
chip-select logic, then when you lay out your board you should
add a couple gates to allow two of the chip selects to be
swapped.

-- 
Grant Edwards
grante@visi.com

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