I am trying to implement IIR filter using CMSIS library in Cortex-M4. i have read so many documents and got confused about co-coefficient's.. [b,a]=butter(6,fc/(fs/2)) [sos,g]=tf2sos(b,a)
this is how i am generating the co-efficients in MATLAB.. but i don't how to use it with CMSIS arm_biquad_cascade_df2T_f32 function..
Matlab SOS matrix will be in the form
SOS = [ b01 b11 b21 1 a11 a21 b02 b12 b22 1 a12 a22 ... b0L b1L b2L 1 a1L a2L ]
but in arm_biquad_cascade_df2T_init_f64 the order is different {b10, b11, b12, a11, a12, b20, b21, b22, a21, a22, ...}
how do i match this? what should i do after generating the SOS matrix in MATLAB?
May be below link help you out: www.keil.com/.../group___i_i_r___lattice.html
ya i gone through that.. i got 2 doubts.. what is the meaning of time-reversed order? and what should be the value of numStages?