change the SDRAM address

[Jason Chen]

hi,all,
I am a newer.I worked on a platform based on MPC8248.
The 64M SDRAM use CS2,and it's base address is 0x00000000,BR2=0x00000041,OR2=fc002cd0.
It's just a simple issue,I want to change the base address of the SDRAM from 0x00000000 to 0x03000000,I thought change the BR2 register to 0x03000041 was ok,but the real thing is that you can read/write the area of 0x03000000 to 0x03ffffff,but the area above the 0x04000000 can not be written and all be read as 0x0.
I want to know am I right to change the base address just by change the BR2?
Is there some other should be change? Or it may connect with a hardware change?

Thanks

Jason