Motorola DSP56156 Manual page 156

If a unity gain is expected from the A/D section, the gain of that filter has to be multiplied
by 1/0.9313 in order to compensate the attenuation of the comb filter at the given decima-
tion ratio (refer to Table 6-14).
Table 6-15 Coefficient of the Filter Shown in Figure 6-23
; Source filter file: "compad125-3.IIR.Filter"
_filter_type
_NSTAGES
Figure 6-24 shows the overall response of the A/D section cascaded with the DSP IIR filter
described above.
MOTOROLA
APPLICATION EXAMPLES
equ BIQUAD_FILTER_TYPE
equ 5
dc $0004
; Biquad stage no. 1
dc $d100
dc $6173
dc $00ce
dc $2259
; Biquad stage no. 2
dc $cb98
dc $5973
dc $fe9b
dc $1fd1
; Biquad stage no. 3
dc $d0af
dc $6b37
dc $f992
dc $1c79
; Biquad stage no. 4
dc $c4a7
dc $5669
dc $d61c
dc $ea20
; Biquad stage no. 5
dc $c391
dc $7c12
dc $dd40
dc $e4dd
DSP56156 ON-CHIP SIGMA/DELTA CODEC
; number of biquadratic stages
; g = 0.0002623691665/2
; -d2_1 = -0.7344004701/2
; -d1_1 = 1.522624504/2
; n2_1 = 0.01255399151/2
; n1_1 = 0.5367057372/2
; -d2_2 = -0.8188274379/2
; -d1_2 = 1.39766389/2
; n2_2 = -0.02180931293/2
; n1_2 = 0.4971358354/2
; -d2_3 = -0.7393345338/2
; -d1_3 = 1.675226724/2
; n2_3 = -0.1004858072/2
; n1_3 = 0.4449126054/2
; -d2_4 = -0.9273113361/2
; -d1_4 = 1.350141276/2
; n2_4 = -0.6545527468/2
; n1_4 = -0.34182236/2
; -d2_5 = -0.9442726739/2
; -d1_5 = 1.938610906/2
; n2_5 = -0.5429834643/2
; n1_5 = -0.4240192654/2
6 - 41