Re: Power calculation using Xpower

Praveen,

It is difficult to estimate how much impact this will have on the power
estimate.
So let me take you through a few points:

Using a post PAR estimate will allow XPower to have an accurate estimate
of
capacitance load on the internal routes so no problem here. If you are
using post MAP
where no SDF is generated then this is a large source of inaccuracy and
is not
recommended.

Now lets look at the timing simulations tend to result in glitches. This
switching translates
into higher activity rates in XPower-> higher power.

I would expect these to be fairly low load signals. Also if you have a
fully synchronous
design this effect will be limited.

Your clocks will be set correctly (high power consuming nets).
If you have met timing (verifed through timing analyser) then other
heavy loaded signals like
clock enables, should be set correctly.

So in summary, if your design is post PAR, fully synchronous and has met
timing, you should
be OK an get an accurate power estimate.

John

praveen wrote:

> hi all,
>
> i am calculating the power consumption using xilinx xpower. For
> generating the VCD file i am not loading the SDF(Standard Delay
> Format) during VSIM. Will it affect the power calculation.
>
> thanks in advance.

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