Problem using ADC with TMS320F28335

I have installed the code composer studio ccsv5 and Matlab support package. I have converted several Matlab programs for open loop system and it works perfectly. However, I wish to implement a closed loop system. In order for my system to works, I have to use ADC in my system. You can find in the attached file, a simple program that I wish to run using DSP. This program emulates a simple PWM generation. Program 1: PWM generation Program 2: PWM generation using hardware interrupt

From ezdsp F28335 Technical reference (Please refer attachment), page 2-12, it is clearly mentioned that I need to connect the ADCLO to AGND. I made the connection, but yet, it has not responded to real ADC values.

For your information, in real implementation, the ADC is connected to a function/signal generator that produce 0 to 3V sine wave.

Thank you,