Are you referring to the EMC Conducted Emission test ?
If yes, which exact reference are you talking about ? As this can vary quite a lot from one device to the next. The basic goal is to generate the maximum of noise by toggling everything that can be.
You may be worried about a certain frequency, or general spectrum ?
No,What I want to achieve is sampling mains votlage and current of any divice like thyristor controlled motor say, by internal ADC and derrive 2nd, 3rd, 5th, 7th harmoinc.