Hi behnam,
Can you please tell me how you are interfacing
the ADC ... from the code that you have posted
it looks like you are using I2C. Can you be more
specific on your interface circuit. You mentioned
that you get garbled data. What's the Master clock
that you are using ? are you sure you are resetting
the ADC properly ? Try to read data from the
configuration registers first.
regards
Ashish