Atmel AVR XMEGA D Series, Manual, Page: 259 / 331

259
8210C–AVR–09/11
Atmel AVR XMEGA D
• Bits 6:4 – REFSEL[2:0]: Reference Selection
These bits selects the reference for the ADC according to Table 21-3 on page 259 .
• Bit 3:2 – 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.
• Bit 1 – BANDGAP: Bandgap Enable
Setting this bit enables the bandgap for ADC measurement. Note that if any other functions are
already using the bandgap, this bit does not need to be set when the internal 1.00V reference is
used for another ADC or if the brownout detector is enabled.
• Bit 0 – TEMPREF: Temperature Reference Enable
Setting this bit enables the temperature sensor for ADC measurement.
21.14.4 EVCTRL – Event Control register
• Bit 7:5 – 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.
• Bit 4:3 – EVSEL[1:0]: Event Channel Input Select
These bits select which event channel will trigger which ADC channel. Each setting defines a
group of event channels, where the event channel with the lowest number will trigger ADC chan-
nel 0, the next event channel will trigger ADC channel 1, and so on. See
Table 21-4 on page
260 .
Table 21-3. ADC reference selection.
REFSEL[2:0] Group Configuration Description
000 INT1V 10/11 of bandgap (1.0V)
001 INTVCC V
CC
/1.6
010 AREFA External reference from AREF pin on PORT A
011 AREFB External reference from AREF pin on PORT B
100 INTVCC2 V
CC
/2
101 - 111 Reserved
Bit 7 6 5 4 3 2 1 0
+0x03 – – – EVSEL[1:0] EVACT[2:0] EVCTRL
Read/Write R R R R/W R/W R/W R/W R/W
Initial Value 0 0 0 0 0 0 0 0