about the power units in the reports of prime time

power units in primetime report

Hi,

Does anyone know how the power unit in the report of Prime time is defined?
It confuses me a lot.

I wrote a module in verilog, synthesized it in DC. Then use the verilog file produced by DC, I simulated and got a VCD file. Then I use prime time to read verilog file and VCD file, to estimate power of the module, which information is recorded in a .rpt file.
But this rpt file does not show the power unit.
Is the power unit in the library the same with that in PT report?
Or is it fixed to be 'W'?

I am using 65nm library from TSMC.
If the unit is 'W', the peak power used seems too much, since it's just a small module. But if the unit is mW, the power is a little too low then.


I have checked the library file, and it says:
-------------------------------------------------------------------------------
capacitive_load_unit (1,pf) ;
voltage_unit : "1V" ;
current_unit : "1mA" ;
time_unit : "1ns" ;
pulling_resistance_unit : "1kohm";


default_operating_conditions : WCCOML ;
capacitive_load_unit (1,pf) ;
voltage_unit : "1V" ;
current_unit : "1mA" ;
time_unit : "1ns" ;
pulling_resistance_unit : "1kohm";

unitTimeName = "ns"
timePrecision = 1000
unitLengthName = "micron"
lengthPrecision = 1000
gridResolution = 5
unitVoltageName = "v"
voltagePrecision = 100000
unitCurrentName = "mA"
currentPrecision = 100
unitPowerName = "mw"
powerPrecision = 1000
unitResistanceName = "ohm"
resistancePrecision = 10000000
unitCapacitanceName = "pf"
capacitancePrecision = 10000000
unitInductanceName = "nh"
inductancePrecision = 100
-------------------------------------------------------------------------------------------

The rpt is as follows:
----------------------------------------------


Attributes
----------
i - Including register clock pin internal power
u - User defined power group

Internal Switching Leakage Total
Power Group Power Power Power Power ( %) Attrs
--------------------------------------------------------------------------------
io_pad 0.0000 0.0000 0.0000 0.0000 ( 0.00%)
memory 0.0000 0.0000 0.0000 0.0000 ( 0.00%)
black_box 0.0000 0.0000 0.0000 0.0000 ( 0.00%)
clock_network 0.0000 0.0000 0.0000 0.0000 ( 0.00%) i
register 0.0000 0.0000 0.0000 0.0000 ( 0.00%)
combinational 1.909e-04 6.973e-05 1.980e-05 2.804e-04 ( 3.89%)
sequential 6.864e-03 3.008e-05 3.003e-05 6.924e-03 (96.11%)

Net Switching Power = 9.981e-05 ( 1.39%)
Cell Internal Power = 7.055e-03 (97.92%)
Cell Leakage Power = 4.983e-05 ( 0.69%)
---------
Total Power = 7.204e-03 (100.00%)

X Transition Power = 0.0000
Glitching Power = 0.0000

Peak Power = 0.2558
Peak Time = 4890.000
---------------------------------------------------------------------------------------

peak power primetime

hi,

as your library file mentions
unitPowerName = "mw"

it does not have any other information, to get the default value, if the value is too less then you have done a good job.

best regards,
chipdesign made easy
https://www.vlsichipdesign.com

My 2 cents...
I guess your concern is about the unitless report... Basically the power unit would be derived using Voltage, Capacitance, Time, and Leakage Power units. If some of these units are not defined in your technology library then the power reports may be unitless.. From your snippet, the .lib ( the library file ) seems to be intact. ..
The reporting command uses units from your first specified linking library. Is tsmc .db the first db specified in your link library? Are there any warnings displayed by this command? You could also check if the units are set as expected by report_units…
Hope this helps!!!