Datasheet

550
Atmel | SMART SAM D20 [DATASHEET]
Atmel-42129K–SAM-D20_datasheet–06/2014
30.8.2 Control B
Name: CTRLB
Offset: 0x1
Reset: 0x00
Property: Write-Protected
z Bits 7:6 – REFSEL[1:0]: Reference Selection
These bits select the reference voltage for the DAC according to Table 30-1.
Table 30-1. Reference Selection
z Bits 5:4 – Reserved
These bits are unused and reserved for future use. For compatibility with future devices, always write these bits to
zero when this register is written. These bits will always return zero when read.
z Bit 3 – VPD: Voltage Pump Disable
This bit controls the behavior of the voltage pump.
0: Voltage pump is turned on/off automatically.
1: Voltage pump is disabled.
z Bit 2 – LEFTADJ: Left-Adjusted Data
This bit controls how the 10-bit conversion data is adjusted in the Data and Data Buffer registers.
0: DATA and DATABUF registers are right-adjusted.
1: DATA and DATABUF registers are left-adjusted.
z Bit 1 – IOEN: Internal Output Enable
0: Internal DAC output not enabled.
1: Internal DAC output enabled to be used by the AC.
z Bit 0 – EOEN: External Output Enable
0: The DAC output is turned off.
1: The high-drive output buffer drives the DAC output to the V
OUT
pin.
Bit76543210
REFSEL[1:0] - VPD LEFTADJ IOEN EOEN
Access R/W R/W R R R/W R/W R/W R/W
Reset00000000
REFSEL[1:0] Reference Selection Description
0x0 INT1V Internal 1.0V reference
0x1 AVCC AV
CC
0x2 VREFP External reference
0x3 Reserved