Re: Power calculation using Xpower

Hi Praveen,

Are you asking what power, given room temperature operation, would send the junction 
temperature
to over 85 degrees Celsius ?

Brendan

praveen wrote:

> John Blaine <[EMAIL PROTECTED]> wrote in message news:<[EMAIL PROTECTED]>...
> > 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.
> >
> > --
>
> hi john,
>
> as u said our design is fully synchronous and our entire design is
> working on only one  clock edge, and more over ther are no latches
> inferred in our design , so chances of glitches are minimal.
>
> so not loading the SDF file will not make much differnce in th power
> estimate i guess.
>
> one more thing i wanted to ask u regarding the power consumption, we r
> using XILINX virtex 2p (XC2VP50 -6 FF1517) . what is the power that is
> tolerable without providing heat sinks.
>
> praveen