I give up. I've search google and atmel for the i/o addresses for the AT91R40008, but can't find any documentation. There are a lot of digital ports and two serial channels, but I can't find info on setting up these devices. Can anyone point me to a url that has this information?
There are no separate I/O instructions in the ARM architecture - all I/O is memory-mapped, in the same way as DEC PDP-11 and later the Motorola micros.
The memory mapping in AT91's is partially fixed on silicon for on-chip memory and I/O.
For the rest of the address space, there are chip select setup registers in the External Bus Interface unit (EBI) which determine the address ranges of the chip selects used. The chip select ranges are limited so that a chip select must be on a natural limit for the chip select block size and the address ranges of different chip selects (or internal addresses) cannot overlap. There are maximum 24 address lines out of the package (corresponding to 16 Mbytes), so there is plenty of address space to select from.
For details, get the ARM7TDMI, AT91X4XX and AT91R40008 data sheets from the Atmel website ().
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