We build own at91 board with an AT45DB642 and 64MB of SDRam. Above I'll describe some details.
At45DB642 is attached to at91rm9200 on CS0 and SDRam is using a 32bits of data path. We already tested both, and they are working without any kind of problem. We wrote data on At45DB642 and read it without errors, the same occured with SDRAM.
What occurs is that when we run a program from internal ram, everything goes fine. But when we try to run some program from SDRam we get an 0xff on debug serial port. And the program doesn't run. We tested, our software, loader.bin and romboot.bin.
Does anybody see something like it?