how i can use prime time px tu make power analysis

[mazouzi]

please can any one tel me how i can use prime time px to analyse the power in SINGOFF:!!

and what containe power model and switching activitie (vcd or saif) and how i can i get them ??

and what is the difference betuine vcd and saif files ??

thanks in advance .

 

[rca]

saif is generated from vcd with vcd2saif.
read the primetime doc.

 

[mazouzi]

thnks rca for responding

please rca can you explain me how prime time px calculate leakage power and internal power using toggling rate and static probability !!! because the tool use also the value of .lib !! how we can write them like Switching power= 1/2 * Tr * C * Vdd^2 !!!!

and how it calculate peak power in time-based mode !!!!

 

[rca]

The saif through the vcd from the simulation provides the value on the std-cell pins.
The SPEF provides the load on the pins.
The .lib provide the power table function of the load and the value on the pins.
This power table provides the leakage and the dynamic power.
So after that, it is quite easy to calculate the power and the peak-power which the strongest value at the time given by the saif.

 

[mazouzi]

i didn't understand you rca the saif or vcd provide the value of toggling rate and static probability i'am right or not !!

 

[rca]

static probability is when you do not have any vcd/saif files.
vcd/saif files is when you have a deterministic simulation.

 

[mazouzi]

thnks a lot rca

so if i understand the vcd or saif contain the switching activity ???

but what we main by annotation switchnig activity !! :-(

 

[rca]

yes, with the annotation switching you estimate the power for the real application.

 

[mazouzi]

do you mean the tool extract the value of signal transition from vcd or saif and use it to calaculat power !!!

really i'am confuseed !!!

 

[rca]

yes
VCD value change dump: that's clarify!, The VCD capture the changed of all signals you want to log and the time.
By transition, in this case, we means the switch from 0 to 1 or 1 to 0, the slew time, this is provided by through the SPEF and the timing engine in primetime.

 

[mazouzi]

thnks for responding rca