Specifications

MC55/56 Hardware Interface Description
Confidential / Released
s
MC55/56_hd_v04.00a Page 91 of 108 24.08.2006
5.7.2 Audio programming model
The audio programming model shows how the signal path can be influenced by varying the
AT command parameters. The model is the same for all three interfaces, except for the
parameters <outBbcGain> and <inBbcGain> which cannot be modified if the digital audio
interface is being used, since in this case the DAC is switched off.
The parameters inBbcGain and inCalibrate can be set with AT^SNFI. All the other
parameters are adjusted with AT^SNFO.
A
D
A
D
Speech coder
neg. gain (attenuation)
0dB; -6db, -12dB; -18dB
+0...42dB in 6dB steps
1k
1k
1k
1k
2.65V
33uF
+
<sideTone>
AT parameters are given in brackets <…>
and marked red and italic.
<outCalibrate[n]>
n = 0...4
<inBbcGain>
<outBbcGain>
Speech decoder
MIC2
TFSDAI, TXDDAI
RFSDAI, RXDDAI
MIC1
<io>
<ep>
<mic>
<inCalibrate>
-
...0dB
8
EP1
EP2
Figure 42: Audio programming model