The output of the FVR, which is connected to the ADC, Comparators, and DAC, is routed through two independent programmable gain amplifiers. Each amplifier can be programmed for a gain of 1x, 2x or 4x, to produce the three possible voltage levels.
The ADFVR[1:0] bits of the FVRCON register are used to enable and configure the gain amplifier settings for the reference supplied to the ADC module.
The CDAFVR[1:0] bits of the FVRCON register are used to enable and configure the gain amplifier settings for the reference supplied to the DAC and comparator module.