Kind Atten: Lothar Miller I am using FFT and IFFT in FFT Transform 5.0 core.I am getting correct result in Radix 2 burst mode, 128 transform size, natural order i/p and o/p width 13 bits and scaled. I am giving an array(128 samples taken from ADC from zero crossing) to FFT core and IFFT .But when I Taken samples random(128 samples and not from zero crossing) my o/p is not proper.why it so? Secondly, Now I implmented pipeline streaming(others configuration same) in place of Radix 2 then o/p is zero. In this case I am using array( from adc o/p 128 sample) and then fft and ifft( same as in radix 2) and taking next 128 samples 127 samples(old)+1 new sample(but in radix 2 all 128 samples are new). sir why o/p is coming zero and I am using loading and unloading same as radix 2. I am writing correct code or not . What i have to modified when I changed radix 2 to pipeline streaming( except scaling in radix 2 14 bit ii.e.01010101010101 and in pipeling 8 bit 01101010).Kindly sort my problem and give me suggestions.

Even after reading your posting twice I have no idea what you mean. The pipeline streaming is the easiest mode, since it only needs a "start" to run an gives you all information, just as index_k, the number of the freq provided.

> Kind Atten: Lothar Miller I'm sorry, I don't have any knwoledge about the FFT cores of any supplier... > I am using FFT and IFFT in FFT Transform 5.0 core. Others who may be able to help should know: Which core on which FPGA?

i guess it is not xilinx, since they go with fft 7.2 ... 8.0 whilest the newer ones operate with axi only

I am using Xilinx 10.1 and FPGA kit virtex 2 pro i.e. XC2VVP30 FF896 7C. I am using FFT IP core V 5.0

Thanks Karsten M. sir for showing your interest in my problem. Sir I am folowing query : 1. I am using ADC(giving 50 hz sine wave and 1.65 dc offset) and taking 128 samples from zero crossing and giving these samples to FFT core and then IFFT core (Kindly note taking 128 samples in one cycle of sine wave i.e. zero to zero crossing). I am geting proper result but when I am taking 128 samples randomly not from zero crossing then getting wrong results why it so? 2.Is scaling schedule is same for radix2 burst and pipeline streaming, if not then what is scaling schedule for pipeline streaming. 3. In radix 2 burst mode VHDL programming , I am taking 128 samples from zero crossing then giving these samples to FFT core for loading samples and then after unloading afterwards I am using IFFT core for loading and unloading of data. Now again I am collecting 128 new samples from zero crossing(from ADC) and repeats the same steps again. (working fine) Now in pipeline streaming I am collecting 128 samples( 127 old + one new) and giving to FFT core for loading and unloding and then IFFT core for loading and unloading. Is I am using pipeline streming right way or not as not getting proper output. 4. If u have some examples for pipeline streaming then send my email i.e. varun_agr@yahoo.com Can anybody solve my problem?