Posted on June 06, 2014 at 23:40ok i found the solution! for every one who's not advance in matlab like me:
to generate coefficients for iir biquad filter in FDATOOL in matlab :
setting parameter in FDATOOL and Design Filter,
go to ''Set Quantization Parameters'' and set filter arithmetic to ''Single precision''.
goto Edit-> Convert Structure and select direct form I or direct form II transposed depend on your requirement.
goto Edit->Reorder and Scale Second order sections. check Scale check box and click apply. you can reorder sections and change other setting here. note that ''scale value constraint''should be unit, this will scale coefficient for unit gain. so the gain matrix G will all be 1; check it in Analysis->Filter Coefficients , all section gain should be 1 and overall gain should be near 1 if not ,change settings in ''Reorder and Scale Second order sections''.
now you can export coefficients to workspace. please not all numbers in 4th column in the sos matrix are 1 (ax0), you have to remove them. and note that matlab equation for iir biquad is alittle different than cmsis dsp library equation so you have to negate the numbers in 5th and 6th columns.thats all!
sorry for my English...
