Unable to read ADC of ADuC7060

My customer is unable to read values coming from ADC configured in differential
input mode in AduC7060. Any example?

The CFTL (CN0214) on the ADI public website measures a thermocouple input in
differential mode. The source code is provided.

http://www.analog.com/en/circuits-from-the-lab/CN0214/vc.html