Hi andred
In order to make sense of the RMS register measurements, follow the below steps:
1. Apply a known input to the voltage channel, say 220Vrms.
2. Read the corresponding VRMS register and note down the register value. Let's say it is 0d'220000.
3. Find the conversion constant: 220/220000= 10^-3 V/LSB. Store this in MCU.
4. Multiply the conversion constant found in step 3 with the future register results and get the input voltage in volts. Let's say, you apply an unknown voltage and read the VRMS register to be 0d'10000. Then to comprehend the result, multiply it with conversion constant => 10000 * 10^-3 = 10Vrms.
Hope this answers your question!
Regards
hmani