Basic Question

Started by Mahendra Reddy in Analog Devices DSPs17 years ago

I recently purchased EZ-Lite 21061 evealuation kit and wants try few FFT programs. I have the integer samples from ADC of the board...

I recently purchased EZ-Lite 21061 evealuation kit and wants try few FFT programs. I have the integer samples from ADC of the board which I want to use as i/p to the FFT program. But the FFT alogorithms talk about real and complex FFT. What is the diff b/w complex and real FFT? Any help in


Multiprocessor FFT prblm

Started by Syed Moinuddin in Analog Devices DSPs14 years ago 1 reply

Dear All, am trying to do fft on ADSP TS201S Ezkit. The code provided by Analog devices is as follows: Processor B is in...

Dear All, am trying to do fft on ADSP TS201S Ezkit. The code provided by Analog devices is as follows: Processor B is in infinite loop (doing nothing setting only syscon register) Processor A is doing FFT's. How can this code be modified so that both pocessors do fft on a given signal from (audio port) or from Fil


AW: AW: optimised autocorrelation

Started by Jens Michaelsen in Analog Devices DSPs15 years ago 1 reply

I must be somewhat wrong, don't get the same results if I do A or B or C: Variant A: b=Acor(a) x=FFT(b); Variant...

I must be somewhat wrong, don't get the same results if I do A or B or C: Variant A: b=Acor(a) x=FFT(b); Variant B: b=FFT(a); y=RMS(b); Variant C: b=FFT(a); c=RMS(b); d=IFFT(c); z=FFT(d);


FFT calculation

Started by girish tatti in Analog Devices DSPs15 years ago

hello sir, I have doubt with FFT. ADSP-2181 supports FFT libraray. I performed 8-point FFT on a series i am not getting the...

hello sir, I have doubt with FFT. ADSP-2181 supports FFT libraray. I performed 8-point FFT on a series i am not getting the exact results Here is the code #include #include #include #define C 8 vo


FFT calculation.

Started by Girish in Analog Devices DSPs15 years ago

hello sir, I have doubt with FFT. ADSP-2181 supports FFT libraray. I performed 8-point FFT on a series i am not getting the...

hello sir, I have doubt with FFT. ADSP-2181 supports FFT libraray. I performed 8-point FFT on a series i am not getting the exact results.plz any body suggest me. Here is the code #include #include #include


Re: AW: Real Symmetric FFT

Started by Jeff Brower in Analog Devices DSPs15 years ago

Andor- > > > the source code for the Real FFT can be downloaded from ADI. It > > > implements a real N-point FFT using a...

Andor- > > > the source code for the Real FFT can be downloaded from ADI. It > > > implements a real N-point FFT using a N/2-point complex FFT, plus > > > some signal reassembling. > > > > > > If the input signal is however re


FFT cycles on BF-533/535

Started by john_baker_s in Analog Devices DSPs15 years ago

Hi all, I downloaded some FFT routines from ADI web site for the Blackfin. The zip file contains radix-4 and radix-2 complex...

Hi all, I downloaded some FFT routines from ADI web site for the Blackfin. The zip file contains radix-4 and radix-2 complex FFT implemented (together with other things) in assembly and corresponding C test files. In the assembly file it is stated that the radix-4 FFT co


Real Symmetric FFT

Started by andor_bariska in Analog Devices DSPs15 years ago 2 replies

Hi friends, the source code for the Real FFT can be downloaded from ADI. It implements a real N-point FFT using a N/2-point...

Hi friends, the source code for the Real FFT can be downloaded from ADI. It implements a real N-point FFT using a N/2-point complex FFT, plus some signal reassembling. If the input signal is however real _and_ symmetric (as is the case for a linear-phase frequency


Urgent (FFT on Blackfin)

Started by khalil in Analog Devices DSPs13 years ago

Hello, I need to perform 512 fft on BF533, I tried to use the "cfft_fr16" C function from the ADSP library , but I didn't get a good...

Hello, I need to perform 512 fft on BF533, I tried to use the "cfft_fr16" C function from the ADSP library , but I didn't get a good result. I used "twidfftrad2_fr16" to generate the fft twiddles and I think it could be the cause of the problem. Is there anyone who has used these functions?


FFT

Started by deckers_dominique in Analog Devices DSPs13 years ago

Hello everybody, I'm trying to do an FFT with the ADSP2181 code from Analog (assembler) in the simulator (visualdsp++3.5). I importe...

Hello everybody, I'm trying to do an FFT with the ADSP2181 code from Analog (assembler) in the simulator (visualdsp++3.5). I importe sampling from matlab (sum of three or more sinus) into DM and, when the FFT is finished, I dump DM to file and I importe them into Matlab. Sometime, there's no problem and sometimes, I don't have the good spectrum.


Testing FFT

Started by Girish in Analog Devices DSPs14 years ago 1 reply

Hello all, How to test FFT for a realtime signal on ADSP-2181 processors ? I also want to know is it possible to display...

Hello all, How to test FFT for a realtime signal on ADSP-2181 processors ? I also want to know is it possible to display the FFT of real time signal on LCD screeen (I mean frequency values) ? Has any one in the group tried out tht ? i:e I


inverse FFT

Started by bojuchen2000 in Analog Devices DSPs14 years ago

Hi, I use DIT method to implement FFT. But while I use the same code to execute inverse FFT, anything else I should be careful...

Hi, I use DIT method to implement FFT. But while I use the same code to execute inverse FFT, anything else I should be careful out there? In the Analog Device application book, only the following two isuues. 1. scale (1/N), and 2. twiddle factor, from (-sin) to (si


don cross fft in blackfin

Started by emailtoprs in Analog Devices DSPs13 years ago 5 replies

hi iam learning on dsp assembly. i need some samples. i have an fft implementation called don cross fft. any body intersted can convert ...

hi iam learning on dsp assembly. i need some samples. i have an fft implementation called don cross fft. any body intersted can convert to blackfin assembly for me.plese dont forget to add good comments. void fft(int inversetransform) { unsigned i, j, k, n; unsigned BlockSize, BlockEnd; double angle_numerator =- 2.0 * PI; double


FFT link

Started by Girish in Analog Devices DSPs15 years ago 1 reply

hi all , where can i get N point FFT assembly code for ADSP-2181 processor.PLZ get me the exact FFT link of anolog devices. ...

hi all , where can i get N point FFT assembly code for ADSP-2181 processor.PLZ get me the exact FFT link of anolog devices. bye Girish ________________________________________________________________________ Yahoo! Messenger - Communicate instantly..."Pi


Regarding FFT

Started by Prashanth Bhushan in Analog Devices DSPs17 years ago 2 replies

Hi, I was going through the FFT code hosted by Analog Devices where they have benchmarked a 128 point real FFT to take just...

Hi, I was going through the FFT code hosted by Analog Devices where they have benchmarked a 128 point real FFT to take just 1160 cycles on ADSP 21062 ! The implementation is split into 4 parts. Out of N stages first part computes the first 2 stages . Second part c


Zoom FFT problem with frequency Shift

Started by yank...@abv.bg in Analog Devices DSPs9 years ago

Hi all I' m new here and I need for advice and example for zoom FFT. I wrote C code for Zoom FFT for BF532 dsp processor, but doesn't work. I can...

Hi all I' m new here and I need for advice and example for zoom FFT. I wrote C code for Zoom FFT for BF532 dsp processor, but doesn't work. I can find my wrongs and I have ground knowledges in C language. I can't make a frequency shift, in my algorithm I multiply my signal x with sin(2*pi*f) for imaginary part and cos(2*pi*f)for real part. Then I make complex FFT and for input signal I give real ...


BF518 - FFT results and Codec Operation

Started by chagai_e in Analog Devices DSPs8 years ago

Hello All, i'm using the bf 518 with eval. board. recently i used the fft (i used the library function - rfft_fr16) on an audio input stream...

Hello All, i'm using the bf 518 with eval. board. recently i used the fft (i used the library function - rfft_fr16) on an audio input stream of different sizes. I then took the samples and the results of the fft and compared it to the results i get on matlab. I noticed a few odd things some related to the the Codec. and I'm wondering if anyone has an explanation.. The Codec: a) the s...


FFT problem

Started by ivan...@hotmail.com in Analog Devices DSPs10 years ago

Hi, I am trying to call an FFT library function from assembly code. I am working with ADSP 21396 processor (SHARC). I picked _cfftn_nonSIMD....

Hi, I am trying to call an FFT library function from assembly code. I am working with ADSP 21396 processor (SHARC). I picked _cfftn_nonSIMD. I've tried using the SIMD version but it doesn't work. Anyway, I don't have to use it since the FFT calculation is not under tight timing constraints. The problem with the nonSIMD version is that it doesn't give correct results for 4096 points. _cfft128...


FFT and ifft with block exponent

Started by steh...@hotmail.com in Analog Devices DSPs9 years ago 3 replies

I am trying to take fft of an audio signal. The buffer length is 1432, so I take 3 FFTs of 512 length each, padding zeros for last execution. This...

I am trying to take fft of an audio signal. The buffer length is 1432, so I take 3 FFTs of 512 length each, padding zeros for last execution. This is just the start so I am taking FFT and then IFFT and play the audio. The problem is that I am not able to get the sound back. The is rhythemic sound in the output. The noise is so high that I am seldom able to hear the original audio, but it is there....


noise from fft() in VDSP library

Started by prasanth rajagopal in Analog Devices DSPs13 years ago 1 reply

hi,    the fft() and ifft() in library of the VDSP gives values which are 4 times scaled..Now if I want to use this for an audio algorithm,...

hi,    the fft() and ifft() in library of the VDSP gives values which are 4 times scaled..Now if I want to use this for an audio algorithm, I am getting large noises.. Is there a remedy? Do everyone get it same? Then where do I get an error free 16 bit implementation of FFT in blackfin? with regards, prasanth