According to LPC936 datasheet, the range for analog input voltage is :Vss-0.2V to Vss+0.2V (Table 13.2, Page 67 of LPC936 datasheet,www.nxp.com). As per the above table input voltage range is 0.4V - which can be represented by 8 bits. So there must be 1 bit change for every (approx) 2mV change in input. So , I would expect 8Bit ADC to give me a value of 0xFF when 0.2V is input at the ADC input pins. But what I observe is that ADC registers return value like 0x30 when 0.2V is given at the input and the value read keeps increasing when input voltage is increased to 0.4V, 0.6V,0.8V etc..

I am not able to locate a document (on www.nxp.com) that describes clearly what is the maximum input analog voltage value at which I should expect to read 0xFF from ADC.

Any pointers to relevant information?

Thanks in advance for the help
KG