Merge pull request arduino#62 from kengdahl/patch-1

Update analogReference.adoc

Author: Stefania

Language/Functions/Analog IO/analogReference.adoc

@@ -21,7 +21,7 @@ subCategories: [ "Analog I/O" ]
 Configures the reference voltage used for analog input (i.e. the value used as the top of the input range). The options are:
 
 * DEFAULT: the default analog reference of 5 volts (on 5V Arduino boards) or 3.3 volts (on 3.3V Arduino boards)
-* INTERNAL: an built-in reference, equal to 1.1 volts on the ATmega168 or ATmega328 and 2.56 volts on the ATmega8 (not available on the Arduino Mega)
+* INTERNAL: an built-in reference, equal to 1.1 volts on the ATmega168 or ATmega328P and 2.56 volts on the ATmega8 (not available on the Arduino Mega)
 * INTERNAL1V1: a built-in 1.1V reference (Arduino Mega only)
 * INTERNAL2V56: a built-in 2.56V reference (Arduino Mega only)
 * EXTERNAL: the voltage applied to the AREF pin (0 to 5V only) is used as the reference.