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265
8210C–AVR–09/11
Atmel AVR XMEGA D
21.15.2
MUXCTRL – MUX Control registers
The MUXCTRL register defines the input source for the channel.
• Bit 7 – Reserved
This bit is unused and reserved for future use. For compatibility with future devices, always write
this bit to zero when this register is written.
• Bit 6:3 – MUXPOS[3:0]: MUX Selection on Positive ADC Input
These bits define the MUX selection for the positive ADC input.
show the possible input selection for the different input modes.
Table 21-9.
Channel input modes, CONVMODE=1 (signed mode).
INPUTMODE[1:0]
Group Configuration
Description
00
INTERNAL
Internal positive input signal
01
SINGLEENDED
Single-ended positive input signal
10
DIFF
Differential input signal
11
DIFFWGAIN
Differential input signal with gain
Bit
7
6
5
4
3
2
1
0
–
MUXPOS[3:0]
MUXNEG[2:0]
MUXCTRL
Read/Write
R
R/W
R/W
R/W
R/W
R
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
Table 21-10.
ADC MUXPOS configuration when INPUTMODE[1:0] = 00 (internal) is used.
MUXPOS[3:0]
Group Configuration
Description
0000
TEMP
Temperature reference
0001
BANDGAP
Bandgap voltage
0010
SCALEDVCC
1/10 scaled V
CC
0011
Reserved
0100-1111
Reserved
Table 21-11.
ADC MUXPOS configuration when INPUTMODE[1:0] = 01 (single-ended),
INPUTMODE[1:0] = 10 (differential) or INPUTPMODE[1:0] = 1 (differential with
gain) is used.
MUXPOS[3:0]
Group Configuration
Description
0000
PIN0
ADC0 pin
0001
PIN1
ADC1 pin
0010
PIN2
ADC2 pin
0011
PIN3
ADC3 pin
0100
PIN4
ADC4 pin
0101
PIN5
ADC5 pin
0110
PIN6
ADC6 pin