Motorola DSP56156 Manual page 175

If a unity gain is expected from the D/A section, the gain of that filter has to be multiplied
by 1/1.1254 in order to compensate the attenuation of the comb filter at the given decima-
tion ratio (refer to Table 6-20).
Table 6-22 Coefficient of the Filter Shown in Figure 6-37
; Source filter file: "compda81.IIR.Filter"
_filter_type
_NSTAGES
Figure 6-38 shows the overall response of the DSP IIR filter cascaded with the D/A sec-
tion.
6 - 60
APPLICATION EXAMPLES
equ BIQUAD_FILTER_TYPE
equ 5
dc $000a
; Biquad stage no. 1
dc $d46c
dc $66ba
dc $fea3
dc $1978
; Biquad stage no. 2
dc $c68a
dc $562a
dc $fc9d
dc $1626
; Biquad stage no. 3
dc $d631
dc $55aa
dc $f8aa
dc $1158
; Biquad stage no. 4
dc $db03
dc $4e6d
dc $e18e
dc $df38
; Biquad stage no. 5
dc $c3da
dc $7bd9
dc $ca80
dc $f59e
DSP56156 ON-CHIP SIGMA/DELTA CODEC
; number of biquadratic stages
; g = 0.0006268648952/2
; -d2_1 = -0.6808814098/2
; -d1_1 = 1.605119592/2
; n2_1 = -0.02132244978/2
; n1_1 = 0.3979240128/2
; -d2_2 = -0.8978265055/2
; -d1_2 = 1.346321716/2
; n2_2 = -0.05290585592/2
; n1_2 = 0.3460722284/2
; -d2_3 = -0.6532654768/2
; -d1_3 = 1.338507259/2
; n2_3 = -0.114654028/2
; n1_3 = 0.2709873534/2
; -d2_4 = -0.5779701159/2
; -d1_4 = 1.225377027/2
; n2_4 = -0.4756898865/2
; n1_4 = -0.512216145/2
; -d2_5 = -0.9398231986/2
; -d1_5 = 1.935136984/2
; n2_5 = -0.8359239371/2
; n1_5 = -0.1622571097/2
MOTOROLA