System Level simulation Problem

Dear All,

I am facing problem in simulating the system built on SOPC builder.The application is for displaying the inputs fed from switches to LED.the onchip RAM is not working as per the simulation waveforms.The chipselect of onchip ram is not triggered.

tools used

Quartus 6.2,

NIOS II 6.1,Modelsim 6.1 evaluation version Altera

Please help me in this regard.Thanks in advance.

Amit Ganguly