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How to do a FFT ? Comment faire une FFT ?

Started by Unknown December 22, 2005
Hello ,



I am a new user of the TMS320C6711 DSP and i would like to know how i
must do to make an fft with this device.

Actually I acquire six tensions with an analog to digital converter and
i would like to analyse the frequencies of these tension.

Thank you per advance for your help

regards

Vincent.W


The devices that i employed :

- OSR 116 acquissition board :
http://www.traquair.com/products/microline/ors116.html
- 6711 board : http://www.traquair.com/products/microline/c6x11cpu.html

I used sp_fftSPxSP.

DSPF_sp_fftSpxSP(FFTLEN,&in[0],&w[0],scratch,brev,2,0,FFTLEN);

This is a mixed radix, cache optimized routine specially made for c67x.
 You can find good docs on the internet.
http://focus.ti.com/docs/apps/catalog/resources/appnoteabstract.jhtml?abstractName=spru657b

The sp means single precision.  The w and brev arguments will need to
be calculated ahead of time.  There is a tool for calculating w.  You
have to be very careful when using TI's optimized routines.  There are
many special requirements - like padding arrays and an even number of
elements.  I suggest you try an example in the emulator to verify it
works.

http://www.signalsguru.net

In article <1135443159.969136.207050@z14g2000cwz.googlegroups.com>, goldfita@signalsguru.net wrote:
>I used sp_fftSPxSP. > >DSPF_sp_fftSpxSP(FFTLEN,&in[0],&w[0],scratch,brev,2,0,FFTLEN); > >This is a mixed radix, cache optimized routine specially made for c67x. > You can find good docs on the internet. >http://focus.ti.com/docs/apps/catalog/resources/appnoteabstract.jhtml?abstractN >ame=spru657b
This worked better for me. http://focus-webapps.ti.com/general/docs/sitesearch/searchsite. tsp?selectedTopic=1653260327&searchTerm=sp_fftSPxSP&Input=New+Search