Input Control
Name:
INPUTCTRL
Offset:
0x10
Reset:
0x00000000
Access:
Write-Protected, Write-Synchronized
Bit3130292827262524
GAIN[3:0]
AccessR/WR/WR/WR/W
Reset0000
Bit2322212019181716
INPUTOFFSET[3:0]INPUTSCAN[3:0]
AccessR/WR/WR/WR/WR/WR/WR/WR/W
Reset00000000
Bit15141312111098
MUXNEG[4:0]
AccessR/WR/WR/WR/WR/W
Reset00000
Bit76543210
MUXPOS[4:0]
AccessR/WR/WR/WR/WR/W
Reset00000

Bits 27:24 – GAIN[3:0]: Gain Factor Selection

Gain Factor Selection

These bits set the gain factor of the ADC gain stage.

GAIN[3:0] Name Description
0x0 1X 1x
0x1 2X 2x
0x2 4X 4x
0x3 8X 8x
0x4 16X 16x
0x5-0xE   Reserved
0xF DIV2 1/2x

Bits 23:20 – INPUTOFFSET[3:0]: Positive Mux Setting Offset

Positive Mux Setting Offset

The pin scan is enabled when INPUTSCAN != 0. Writing these bits to a value other than zero causes the first conversion triggered to be converted using a positive input equal to MUXPOS + INPUTOFFSET. Setting this register to zero causes the first conversion to use a positive input equal to MUXPOS.

After a conversion, the INPUTOFFSET register will be incremented by one, causing the next conversion to be done with the positive input equal to MUXPOS + INPUTOFFSET. The sum of MUXPOS and INPUTOFFSET gives the input that is actually converted.

Bits 19:16 – INPUTSCAN[3:0]: Number of Input Channels Included in Scan

Number of Input Channels Included in Scan

This register gives the number of input sources included in the pin scan. The number of input sources included is INPUTSCAN + 1. The input channels included are in the range from MUXPOS + INPUTOFFSET to MUXPOS + INPUTOFFSET + INPUTSCAN.

The range of the scan mode must not exceed the number of input channels available on the device.

Bits 12:8 – MUXNEG[4:0]: Negative Mux Input Selection

Negative Mux Input Selection

These bits define the Mux selection for the negative ADC input. selections.

ValueNameDescription
0x00 PIN0

ADC AIN0 pin

0x01 PIN1

ADC AIN1 pin

0x02 PIN2

ADC AIN2 pin

0x03 PIN3

ADC AIN3 pin

0x04 PIN4

ADC AIN4 pin

0x05 PIN5

ADC AIN5 pin

0x06 PIN6

ADC AIN6 pin

0x07 PIN7

ADC AIN7 pin

0x08-0x17

Reserved

0x18 GND

Internal ground

0x19 IOGND

I/O ground

0x1A-0x1F

Reserved

Note: 1. Only available in SAM R21G.

Bits 4:0 – MUXPOS[4:0]: Positive Mux Input Selection

Positive Mux Input Selection

These bits define the Mux selection for the positive ADC input. The following table shows the possible input selections. If the internal bandgap voltage or temperature sensor input channel is selected, then the Sampling Time Length bit group in the SamplingControl register must be written.

MUXPOS[4:0] Group configuration Description
0x00

PIN0

ADC AIN0 pin

0x01

PIN1

ADC AIN1 pin

0x02

PIN2

ADC AIN2 pin

0x03 PIN3 ADC AIN3 pin
0x04 PIN4 ADC AIN4 pin
0x05

PIN5

ADC AIN5 pin

0x06

PIN6

ADC AIN6 pin

0x07 PIN7 ADC AIN7 pin
0x08 PIN8 ADC AIN8 pin
0x09 PIN9 ADC AIN9 pin
0x0A PIN10 ADC AIN10 pin
0x0B PIN11 ADC AIN11 pin
0x0C

PIN12

ADC AIN12 pin

0x0D

PIN13

ADC AIN13 pin

0x0E

PIN14

ADC AIN14 pin

0x0F

PIN15

ADC AIN15 pin

0x10 PIN16 ADC AIN16 pin
0x11 PIN17 ADC AIN17 pin
0x12 PIN18 ADC AIN18 pin
0x13 PIN19 ADC AIN19 pin
0x14-0x17   Reserved
0x18 TEMP Temperature reference
0x19 BANDGAP Bandgap voltage
0x1A SCALEDCOREVCC 1/4 scaled core supply
0x1B SCALEDIOVCC 1/4 scaled I/O supply
0x1C DAC DAC output
0x1D-0x1F   Reserved