hi,

i plan to use one chip sdram on at91sam9261 board, the demobaord use 2pcs sdram (32bit bus), how to change u-boot/linux code when i only use one 16bit sdram?

szh

I've done that. For testing, I unsoldered one sdram chip. Then, you have to change the sdram initialization (if I remember correctly, that was done in dataflashboot) and the SDRAM size in u-boot (that is given to kernel). Then you have to modify your sdram controller initialization tcl scripts in sam-ba, too. This did the trick.
Actually, the performace difference between one and two chip configuration was very minimal. The difference could be seen only on context switch intensive tests, and even there it was not very bad.