Motorola DSP56156 Manual page 159

If a unity gain is expected from the D/A section, the gain of that filter has to be multiplied
by 1/1.7366 in order to compensate the attenuation of the comb filter at the given decima-
tion ratio (refer to Table 6-14).
Table 6-16 Coefficient of the Filter Shown in Figure 6-25
; Source filter file: "compda125-3.IIR.Filter"
_filter_type
_NSTAGES
Figure 6-26 shows the overall response of the DSP IIR filter cascaded with the D/A sec-
tion.
6 - 44
APPLICATION EXAMPLES
equ BIQUAD_FILTER_TYPE
equ 5
dc $0004
; Biquad stage no. 1
dc $cfea
dc $62ed
dc $fea9
dc $1cfb
; Biquad stage no. 2
dc $cbb2
dc $5a69
dc $fc5b
dc $1a08
; Biquad stage no. 3
dc $cfd3
dc $6ca5
dc $f760
dc $1614
; Biquad stage no. 4
dc $c43d
dc $5797
dc $dd44
dc $e362
; Biquad stage no. 5
dc $c363
dc $7c4e
dc $ce92
dc $f27d
DSP56156 ON-CHIP SIGMA/DELTA CODEC
; number of biquadratic stages
; g = 0.0002663555811/2
; -d2_1 = -0.7513359622/2
; -d1_1 = 1.545692138/2
; n2_1 = -0.02093532311/2
; n1_1 = 0.4528080448/2
; -d2_2 = -0.8172580463/2
; -d1_2 = 1.412661966/2
; n2_2 = -0.05697205133/2
; n1_2 = 0.4067669553/2
; -d2_3 = -0.7527639534/2
; -d1_3 = 1.697593082/2
; n2_3 = -0.1347748217/2
; n1_3 = 0.3449803812/2
; -d2_4 = -0.9337611394/2
; -d1_4 = 1.368618028/2
; n2_4 = -0.5427221805/2
; n1_4 = -0.4471418369/2
; -d2_5 = -0.9470992435/2
; -d1_5 = 1.942249147/2
; n2_5 = -0.7723597585/2
; n1_5 = -0.211141353/2
MOTOROLA