30.5.3 Control C

Name: CTRLC
Offset: 0x02
Reset: 0x00
Property: -

Bit 76543210 
 SAMPCAPREFSEL[1:0]PRESC[2:0] 
Access RR/WR/WR/WRR/WR/WR/W 
Reset 00000000 

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.
ValueDescription
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.

ValueNameDescription
0x0 INTERNAL Internal reference
0x1 VDD VDD
0x2 VREFA External reference VREFA
Other - Reserved

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).

ValueNameDescription
0x0 DIV2 CLK_PER divided by 2
0x1 DIV4 CLK_PER divided by 4
0x2 DIV8 CLK_PER divided by 8
0x3 DIV16 CLK_PER divided by 16
0x4 DIV32 CLK_PER divided by 32
0x5 DIV64 CLK_PER divided by 64
0x6 DIV128 CLK_PER divided by 128
0x7 DIV256 CLK_PER divided by 256