Disable One SDRAM of OMAP-L137

I'm developing on OMAP-L137 EVM.

There are two SDRAM on this EVM. 

I want to test SDRAM performance. How to disable one SDRAM?  (Hardware remove? or disable by registers?)

When OMAP-L137 EVM work with only one SDRAM, I could verify whether same program could run at C6743.

(C6743 can access only one SDRAM. OMAP-L137 EVM access two SDRAM)