MC45 Hardware Interface Description
P R E L I M I N A R Y
MC45_HD_01_V00.02a
Page 81 of 90
12.08.2002
6.5 Electrical characteristics of the voiceband part
6.5.1 Setting audio parameters by AT commands
The audio modes 2 to 6 can be adjusted according to the parameters listed below. Each
audio mode is assigned a separate set of parameters.
Table 30: Audio parameters adjustable by AT command
Parameter
Influence to
Range
Gain range
Calculation
inBbcGain
MICP/MICN analogue amplifier gain
of baseband controller before ADC
0...7
0...42dB
6dB steps
inCalibrate
digital attenuation of input signal
after ADC
0...32767 -
∞
...0dB
20 * log
(inCalibrate/
32768)
outBbcGain
EPP/EPN analogue output gain of
baseband controller after DAC
0...3
0...-18dB
6dB steps
outCalibrate[n]
n = 0...4
digital attenuation of output signal
after speech decoder, before
summation of sidetone and DAC
present for each volume step[n]
0...32767 -
∞
...+6dB
20 * log (2 *
outCalibrate[n]/
32768)
sideTone
digital attenuation of sidetone
is corrected internally by outBbcGain
to obtain a constant sidetone
independent of output volume
0...32767 -
∞
...0dB
20 * log
(sideTone/
32768)
Note: The parameters inCalibrate, outCalibrate and sideTone accept also values from 32768
to 65535. These values are internally truncated to 32767.
