i A PHYSICAL IMPLEMENTATION WITH CUSTOM LOW POWER ...

Internal Power
Internal Power is the power dissipated by the cell because of the charging and
discharging of the nodes internal to the cell. In addition to that, short-circuit current that results
when both the PMOS and NMOS transistors are ON (as in the case of an inverter) dissipates
short-circuit power. This power is also accounted in the internal power consumption. Short-
circuit power is a function of the input transition time. For slow transition times, the short circuit
power is high as compared with fast transition times because the NMOS and PMOS transistors
are simultaneously ON for a longer duration of time. Short circuit power is also influenced by
the sizes of the transistors.
3.2 PRIMEPOWER POWER ESTIMATION FLOW
Prime power is gate-level power analysis tool for analyzing the power dissipation of standard-
cell based designs [5]. Prime power supports event-based and statistical activity based power
analysis at the gate level.
Event based power analysis uses event driven simulation to calculate the power
consumed at every event. Event based power analysis is actually dependent on the input vector
and when averaged over a large number of input vectors can give a very accurate estimate of the
power consumed by the chip.
Statistical Activity based power analysis uses a probabilistic and statistical estimation
algorithm to calculate the average power. It is mostly vector free or has weak vector dependence
[5].
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