Hi All,

I am using the flow in the tutorial here for power analysis in encounter. For my testcase, encounter doesn't seem to be reading the energy numbers defined in the internal_power() section of the .lib. It gives some numbers in the power report but I have no clue where they are coming from. I commented out the internal_power section in the .lib, and encounter still generated power numbers! How does it do that without the info in the .lib?

Thanks
Mallika

I believe there are at least 3 components: cell power, interconnect power and leakage power. Interconnect power can be determined by the R and C of the wire and its voltage. So it could be that this is the fraction of the total power you are seeing. Also, cell leakage can be a constant for a cell. In that case it might be defined outside the internal power section (not sure). I nothing adds up then there is likely a unit mismatch. It might be worthwhile to simulate a small circuit with Ultrasim or Nanosim and compare the power to SOCE. Should match within 20% or so.

Power is comprised of static power and dynamic power.

Static power is the power wasted due to leakage power. This will be there even when there is no acticity happening (change of state) and will vary from one state to another.

Dynamic power comprises of switching power and internal power.

Internal power is the short circuit power that is consumed due to a short circuit current which flows when both pmos and the nmos are on when the cell switches.

Switching power is the power consumed by the lumped load on the cell.

For most libraries switching power will be more than the internal power for most designs.

Refer to the synopsys primepower manual for more details about how these are calculated.