#define ADC_REF_INT 0x00000000 // Internal reference
#define ADC_REF_EXT_3V 0x00000001 // External 3V reference
#define ADC_REF_EXT_1V 0x00000003 // External 1V reference
As per adc.h file for adc driver for the Tiva™ TM4C1294NCPDT Microcontroller,these values are defined as vref value setting options.
if we relate this to data sheet for ADC Control (ADCCTL), offset 0x038, we set VREF bit as 1 for ADC_REF_EXT_3V and reset VREF bit as 0 for ADC_REF_INT.
how do we derive the logic for ADC_REF_EXT_1V .