Thank you for your answer.I've checked MPU register and there are 3 protected regions but all of them are refering to D2 RAM region.The problem starts to be really annoying becouse I haven't made any progress since monday.

Hello,I am facing same problem, FMC performs 8 instead of 1 write operation. I have remaped FMC to 0xC0000000, but without result. Theoretically 0xC0000000 region of memory is not cacheable, so problem should be solved. Maybe there is problem with so...