This bit field selects the Reference Voltage for both DACs.
Note:
- The reference selection of the DAC will reset to ‘0’ (VREFAU) if the DAC
Software Reset (CTRLA.SWRST) is used.
- When the internal bandgap reference (INTREF) is selected as reference voltage
(CTRLB.REFSEL = 0x3), the DAC Startup Ready bits value (STATUS.READY0,
STATUS.READY1) is not correct for the first DAC Conversion after device
power-up or after wake-up from Standby Low-Power mode. Disregard STATUS.READY0
and STATUS.READY1 bits for the first DAC conversion and check instead that the
Data Buffer 0/1 Empty bits are set (INTFLAG.EMPTY0 = 1, INTFLAG.EMPTY1 =
1).
| Value | Name | Description |
|---|
| 0x0 |
VREFAU |
Unbuffered external voltage reference
(not buffered in DAC, direct connection) |
| 0x1 |
AVDD |
Voltage
supply |
| 0x2 |
VREFAB |
Buffered external voltage reference
(buffered in DAC). This buffered external voltage reference option can be used
when the applied external input reference voltage has insufficient drive
current. |
| 0x3 |
INTREF |
Internal bandgap
reference |
