I did a brief read of the specs for the flash device. I dare say there's two of these devices to give you 32 bit data path. As for the processor you're using, I have no knowlege of these so the bus architecture I do not know. Firstly read the data sheet carefully! There's lots of gotcha's in there! Also, you must be careful to ensure no one else is accessing those flash devices - interrupt routines etc as they will violate the sequence requirements. Disable interrupts whilst you wish to flash - also remember that you cannot execute code from these units once you try to flash them! Make sure your flashing code is in ram or another part of memory. That's about all I can suggest.