Hi,
I am using CMSIS library for FFT computation in LPC54607J256BD208E.
IDE: MCXpresso IDE v 10.3.1_2233
I am trying to optimize my code size to fit a bootloader along with application code.
On analysis of Map size, I found that cmsis fft constants take up a lot spcae.
Constants | Size |
twiddleCoef_2048 | 16384 |
twiddleCoef_rfft_4096 | 16384 |
twiddleCoef_rfft_2048 | 8192 |
twiddleCoef_1024 | 8192 |
armBitRevIndexTable2048 | 7616 |
twiddleCoef_512 | 4096 |
twiddleCoef_rfft_1024 | 4096 |
armBitRevIndexTable1024 | 3600 |
twiddleCoef_256 | 2048 |
twiddleCoef_rfft_512 | 2048 |
Total | 72656 |
Is there any way to optimize these constants or is there any code optimized fft library for this microcontroller.
Thanks and best regards,
Prasanna
> Is there any way to optimize these constants or is there any code optimized fft library for this microcontroller.
Optimize for what ? You can either optimize for speed, for size, or a mixture (=compromise) of both.
The usage of the named pre-calculated constants for FFT is a speed optimization of that algorithm.
You can try implementing any other FFT algorithm, if you wish. But be aware of the limitations of "float" versus "double".