What pins can be used for Analog Comparator Inputs?

Does anyone know or can can anyone point me to a source for this? I need to know what pins of the standard arduino connectors can be used as inputs to the SAMD21G18. Thanks Wade Hassler

Hmmm... that appears to be in this table: https://github.com/arduino/ArduinoCore-samd/blob/master/variants/arduino_zero/variant.cpp#L19 Those pins with "AC/AIN" in the "Comments" column.