Intel® Quartus® Prime Software
Intel® Quartus® Prime Design Software, Design Entry, Synthesis, Simulation, Verification, Timing Analysis, System Design (Platform Designer, formerly Qsys)
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Can unified FFT IP accurately calculate double precision FFT?

ming1
Beginner
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Hi,

Recently,  I used the single precision option in Unified FFT IP.

It works well. (256point ,sampling frequency is 12800hz. The real input is 100sin2pi50t, the imag input is 0, and the output of FFT IP is -12800 at the frequency of 50hz , which equals to 100*(256/2).)

ming1_0-1638448423703.png

ming1_1-1638448596594.png

 

 

 


But when I change single precision to double precision in FFT IP  and change the input data into double precision floating-point numbers of the same size, it is not -12800 at the frequency of 50hz.

ming1_2-1638448645289.pngming1_3-1638448670936.png

 

Do I need to add other designs to realize Double precision fft or Double precision FFT
cannot be realized with Unifed FFT IP?

ming1_4-1638449254158.png

If you have any idea, can you please tell me?  I've been bothering about it for a long time.

Thanks!

Regards!

 

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