37.7.3 Reference Control
| Name: | REFCTRL | 
| Offset: | 0x02 | 
| Reset: | 0x00 | 
| Property: | PAC Write-Protection, Enable-Protected | 
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
| REFCOMP | REFSEL[3:0] | ||||||||
| Access | R/W | R/W | R/W | R/W | R/W | ||||
| Reset | 0 | 0 | 0 | 0 | 0 | ||||
Bit 7 – REFCOMP Reference Buffer Offset Compensation Enable
The gain error can be reduced by enabling the reference buffer offset compensation. This will increase the start-up time of the reference.
| Value | Description | 
|---|---|
| 0 | Reference buffer offset compensation is disabled. | 
| 1 | Reference buffer offset compensation is enabled. | 
Bits 3:0 – REFSEL[3:0] Reference Selection
These bits select the reference for the ADC.
| Value | Name | Description | 
|---|---|---|
| 0x0 | INTREF | internal reference voltage, supplied by the bandgap (refer to SUPC VREF.SEL for voltage level information) | 
| 0x1 | INTVCC0 | 1/1.6 AVDD | 
| 0x2 | INTVCC1 | 1/2 AVDD (only for AVDD > 4.0V) | 
| 0x3 | VREFA | External reference | 
| 0x4 | DAC | DAC internal
                     output (not available on all device variants. Refer to the Configuration Summary chapter for the list of variants embedding the DAC.)  | 
            
| 0x5 | INTVCC2 | AVDD | 
| 0x6 - 0xF | Reserved | 
