Update Language/Functions/Analog IO/analogReference.adoc

Author: karlsoderby

Language/Functions/Analog IO/analogReference.adoc

@@ -35,7 +35,7 @@ Arduino SAMD Boards (Zero, etc.)
 * AR_INTERNAL1V65: 1/2 VDDANA = 1.65V reference in a 3.3 V system
 * AR_INTERNAL2V23: 1/1.48 VDDANA (only for VDDANA > 2.0V) = 2.23V reference in a 3.3V system
 * AR_EXTERNAL: the voltage applied to the AREF pin is used as the reference
-(For Details see Atmel SAMD21 Data sheet, 32.8.2 Reference Control)
+(For Details see Atmel SAMD21 Data sheet, 33.8.2 Reference Control)
 
 Arduino SAM Boards (Due)