Microchip Technology megaAVR 0 Series Manual page 424

28.5.3 Control C
Name: CTRLC
Offset: 0x02
Reset: 0x00
Property: -
Bit 7
Access R
Reset 0
Bit 6 – SAMPCAP Sample Capacitance Selection
This bit selects the sample capacitance, and hence, the input impedance. The best value is dependent on
the reference voltage and the application's electrical properties.
Value Description
0 Recommended for reference voltage values below 1V.
1 Reduced size of sampling capacitance. Recommended for higher reference voltages.
Bits 5:4 – REFSEL[1:0] Reference Selection
These bits select the voltage reference for the ADC.
Value Name
0x0 INTERNAL
0x1 VDD
0x2 VREFA
Other -
Bits 2:0 – PRESC[2:0] Prescaler
These bits define the division factor from the peripheral clock (CLK_PER) to the ADC clock (CLK_ADC).
Value Name
0x0 DIV2
0x1 DIV4
0x2 DIV8
0x3 DIV16
0x4 DIV32
0x5 DIV64
0x6 DIV128
0x7 DIV256
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2018 Microchip Technology Inc.
6 5
SAMPCAP REFSEL[1:0]
R/W R/W
0 0
Description
CLK_PER divided by 2
CLK_PER divided by 4
CLK_PER divided by 8
CLK_PER divided by 16
CLK_PER divided by 32
CLK_PER divided by 64
CLK_PER divided by 128
CLK_PER divided by 256
Analog-to-Digital Converter (ADC)
4 3
R/W R
0 0
Description
Internal reference
V
DD
External reference V
REFA
Reserved.
Datasheet Preliminary
®
megaAVR 0-Series
2 1
PRESC[2:0]
R/W R/W
0 0
DS40002015A-page 424
0
R/W
0