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cosmiac
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Registered: ‎06-06-2012

Questions about Power Analyzer

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Hello,

 

I was wondering how the Xilinx Power Analyzer comes up with its power data. Does it run the system through some kind of benchmark? Is the data just the power consumption for the part alone or the entire design?

 

Shouldn't a design implemented on with a Spartan 6 LX75T Development Kit +MicroBlaze@66MHz consume less power than the same VHDL design on a Spartan 6 LX150T Development Kit + MicroBlaze@100Mhz?

 

Thanks!

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austin
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Registered: ‎02-27-2008

XPA (the analyzer) will use a .vcd simulation stimulus file, and calculate the togfgling at all nodes fotr the dynamic power, and add that to the static power.


If you do not provide the .vcd file, it assumes a 50% toggling of all inputs, the clock frequencies you specify, and does tghe same set of calculations.

 

The less information you give it, the more error there is (garbage in = garbage out).  The better the information you give it, the better the estimate it will deliver.



Austin Lesea
Principal Engineer
Xilinx San Jose

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austin
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9,711 Views
Registered: ‎02-27-2008

XPA (the analyzer) will use a .vcd simulation stimulus file, and calculate the togfgling at all nodes fotr the dynamic power, and add that to the static power.


If you do not provide the .vcd file, it assumes a 50% toggling of all inputs, the clock frequencies you specify, and does tghe same set of calculations.

 

The less information you give it, the more error there is (garbage in = garbage out).  The better the information you give it, the better the estimate it will deliver.



Austin Lesea
Principal Engineer
Xilinx San Jose

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cosmiac
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what is confusing me in our design, is that using the Xpower analyzer with our design, and an embedded Microblaze processor clocked at 100 Mhz is averaging about 700 mW of power use, but then the same exact design on an LX75T with the embedded Microblaze at 66Mhz is averaging 761 mW of power consumption. Is the LX150T better optimized for low power consumption than the LX75T perhaps?

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austin
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Nope,


There is something else going on that you are missing.


It this static + dynamic?

 

If it is, look at them separately.  Static increases roughly lineraly with part size, twice as big is twice the static component.


The same logic, in the same family, at the same frequency, is roughly the same dynamic power.

 

 

Austin Lesea
Principal Engineer
Xilinx San Jose
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cosmiac
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The XPA summary shows both dynamic and static but the numbers I refered to were for total power. I didn't change any settings between the two XPA reports, just the microblaze settings and spartan 6 boards. How do you setup and add a .vcd simulation stimulus file?

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cosmiac
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Any chance you could point me to the Kintex 7 Embedded kit .bsb file?

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austin
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http://www.xilinx.com/support/documentation/k7embd_13-4.htm
Austin Lesea
Principal Engineer
Xilinx San Jose
cosmiac
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Thanks for your help!

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sushantm
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Can anyone please share the links for Documents which will help/guide us in using the Power analyser.

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cosmiac
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prathyu.931
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prathyu.931
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