43.7.7 ADREF

ADC Reference Selection Register
Name: ADREF
Address: 0x3F8

Bit 76543210 
    NREF  PREF[1:0] 
Access R/WR/WR/W 
Reset 000 

Bit 4 – NREF ADC Negative Voltage Reference Selection

ValueDescription
1 VREF- is connected to external VREF-
0 VREF- is connected to AVSS

Bits 1:0 – PREF[1:0] ADC Positive Voltage Reference Selection

ValueDescription
11 VREF+ is connected to internal Fixed Voltage Reference (FVR) module
10 VREF+ is connected to external VREF+
01 Reserved
00 VREF+ is connected to VDD