i want to use fix point FFT, but ROM consumption very high,so can you help to decrease the ROM consumption?

[富国林]

    arm_rfft_fast_init_f32(&S,  fftSize);

    arm_rfft_fast_f32(&S,testInput_f32_10khz,testOutput,0);   this function need 80kB ROM to save the coffee, but i just need 512 point FFT.

if i use rfft_q31,the ROM consumption over 130kB, so how to optimize it?

[xiangjun_rong]

Hi,GuoLing,

Pls refer to the file arm_common_tables.c located at:C:\Freescale\KSDK_1.1.0\platform\CMSIS\DSP_Lib\Source\CommonTables, the file contains the sine/cosin table for FFT, if you use only 512 points FFT, you can remain the const float32_t twiddleCoef_512[1024] array and delete all the other array in order to save ROM space. BTW, I suggest you copy the arm_common_tables.c to another file before you modify it.

BR

Xiangjun Rong

[PatriciaTeran]

Hi,

would it be possible for you to tell me which part are you using?

Thanks in advance

[富国林]

i am really want to use rfft_q31.

[soledad]

Hello,

Are you using a Kinetis device? if there is, which device are you using???

Are you using CodeWarrior???

Regards

Sol

[富国林]

yes, the device is KL16, and i am using IAR7.4.