While simulating 16 bit RCA in virtuos Analog Design environment window select OUTPUT ..> saveall.
In save all options enable all options.
In waveform window select Browser..> results...> open results , then Select Waveform Data base window will open ,here select psf file. In left side of waveform window we can observe a browser. In browser doble click on tran option
Here we can have current , voltage and power signals at various parts of the design.
Double click on pwr option. Then we can observe wave of power signal in waveform window.
select pwr signal and do as follows to get avg power
In Waveform window goto TOOL option open calculator.
In calculator go for Functional panel select average function and then clik on evaluate button.
The obtained value is the average value.