Hi Raghu,

I'm not familiar with that particular uC, but others I have worked with have had some ADC inputs with different specs than others. For example, some ADC inputs were powered by digital Vcc instead of analog Vcc, and as a result the available resolution was different. It sometimes takes real close reading of the datasheet to find these potential problems.

Of course your problem could simply be fried IO pins... I've had to replace chips before because one or more pins had been zapped, while everything else was just fine.

Dennis