uTasker project developer and internaltional embedded firmware consultant

Re: CMSIS CFFT bit reversal table -how to generate?

Reply posted 3 years ago (09/17/2018)
A couple of notes:1) There is an ARM /mbed forum but there are virtually no responses there (especially not from ARM)2) I have seen other people trying to do the...

Re: CMSIS CFFT bit reversal table -how to generate?

Reply posted 3 years ago (09/17/2018)
The CMSIS code selects the FFT to be used based on the length as follows:    switch (L)    {    case 16:    case 128:    case 1024:       ...

Re: CMSIS CFFT bit reversal table -how to generate?

Reply posted 3 years ago (09/17/2018)
HiCMSIS is ARM's "Cortex Microcontroller Software Interface Standard"https://developer.arm.com/embedded/cmsisI tried with different bit-reversal codes:static int...
Hi All The ARM CMSIS  FIXED POINT FFTs uses a bit reversal table at the end of the FFT calculation to transpose the output bins to their linear ordering....

Re: ARM CMSIS FFT - does it produce correct results?

Reply posted 5 years ago (02/01/2017)
Hi AllI decided not to use the RFFT and stick with the CFFT one - just constructing the required complex data at the input.This requires the additional copy and...

Re: ARM CMSIS FFT - does it produce correct results?

Reply posted 5 years ago (01/14/2017)
TimI think that you have hit the nail on the head. arm_cfft_f32() looks to really need complex input and doesn't just give complex output. Reading the documents...

Re: ARM CMSIS FFT - does it produce correct results?

Reply posted 5 years ago (01/13/2017)
MikeI am using single-precision floating point (the routine used is for that). Since I have an FPU in the final processor this is the best choice in my case rather...

Re: ARM CMSIS FFT - does it produce correct results?

Reply posted 5 years ago (01/13/2017)
HiThere is no sampling frequency involved since the tests are just in static buffers.RegardsMark

Re: ARM CMSIS FFT - does it produce correct results?

Reply posted 5 years ago (01/13/2017)
RickMany thanks for the very wise advice. I have just performed the 4 tests.1.I get 360 rather than 512 but only DC.2.This test is as expected.3.This starts off...

Re: ARM CMSIS FFT - does it produce correct results?

Reply posted 5 years ago (01/13/2017)
Hi MikeThe magnitude calculation is arm_cmplx_mag_f32(fft_input_buffer, fft_magnitude_buffer, 256);, however it is only doing a root-mean-square of the imaginary...
Hi AllDoes anyone have experience with the #ARM CMSIS #FFT? Specifically the floating point implementation arm_cfft_f32()?Although testing the code using the ARM...

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