Physics of Power

Dynamic power -> 

Switching Power: is the Power spent ->

Charging and discharging the capacitance of the output net: called load power or CV2 power. Switching power is a function of switching activity and load capacitance, it is data dependent

Short Circuit Power:  is the Power dissipated -> 

Inside the gate when switching, also known as internal power or crowbar power

Total of internal power and switching power called dynamic power

Static Power: is the power when: 

No signals are changing values; means when device is not functional; means the Leakage Power or is a calculation of leakage power called static power

IR Drop: 

Dynamic IR Drop: Dependent on the switching activity of the standard cells themselves.  

                                             Vdynamic_drop = L (di/dt)

1. (RC)max corner -> RCWorst corner. PVT Conditions -> impact of the standard cells. Highest switching activity for standard cells --> ff corner High V & High T  High T > More resistance -> more RC

Static IR drop:  Vstatic_drop = Iavg x Rwire 

Depends on the RC of the power grid connecting the power supply to the respective standard cells

R-> Higher metal layers ->  wide wires -> lower resistance -> low IR drop -> lesser  impact on setup-timing. 

C-> Capacitance of metal wires ->  combination of ground and the coupling capacitance -> if  capacitance is too large -> More IR drop:: 

            Long wire length               - >  Higher wire cap.

            High fan-out of the net       ->  Higher load-cap

            High routing congestion      -> Higher coupling capacitance