CSTEP does not single-step in C file

Hi,
I used the Command Window of CCS and tried CStep . But, this does not
single-step in C file.
Should i need to configure/enable something for doing this.

In CCS manual i find the below info :
"The CSTEP command is similar to STEP, but CSTEP always single-steps in
terms of a C statement."

I do not find any specific things to configure in CCS to enable the
proper working of CSTEP command in
the command window of CCS. I am using OMAP,CCS & XDS510-USB(PDM) .

Kindly let me know some solutions for this.

Thx in advans,
Karthik Balaguru