REFSEL=INTREF
Reference Control
| REFSEL | Reference Selection 0 (INTREF): Internal Bandgap Reference 2 (INTVCC0): 1/2 VDDANA 3 (INTVCC1): VDDANA 4 (AREFA): External Reference A 5 (AREFB): External Reference B 6 (AREFC): External Reference C (only on ADC1)  |  
| REFCOMP | Reference Buffer Offset Compensation Enable  |