I am using the ADC on a K20F120, and getting results that are exactly half what they should be (according to an oscilloscope which I am measuring the input with). My configuration is as follows:
core clock = 120 MHz
bus clock = 60 MHz
ADC clock = 7.5 MHz
ADC mode = 16 bit differential
ADC trigger = software triggered, free running
ADC triggers DMA transfers on conversion complete
ADC is calibrated before being used
ADC is running at correct speed
No PGA configured
ADC range is 0V-3V (approximately the same as Vdd)
I can post the configuration if that would help (I am not using processor expert), but I am wondering if anyone has encountered this issue before. It looks as if the results are being right-shifted. The problem could be something with the ADC or DMA.
Any input would be greatly appreciated. Thanks for reading my post!