General Filtered in sigmastudio use,I use an external chip control ADSP21489，
There are some problems but in the General Filter here.
When "General Filter" gain value is zero or direct ( equivalent to:b0 = 1, b1 = 0, b2 = 0, a1 = 0, a2 = 0),System began slowly unstable until no sound.
but "General Filter" Gain changed to other values found no problem .
I do not understand is directly sigmastudio control was not aware that the problem,
and there is a strange phenomenon as shown below:
In sigmastudio ,Why a1, a2 is equal to 0 transmitted data but it will be 0x80000000.
Can help analyze problem?