Specifications

XT55 Hardware Interface Description
Confidential / Preliminary
s
mo b i l e
XT55_hd_v00.02 Page 99 of 116 17.03.2004
6.6 Electrical characteristics of the voiceband part
6.6.1 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 analog amplifier gain of
baseband controller before ADC
0...7 0...42dB 6dB steps
inCalibrate digital attenuation of input signal
after ADC
0...32767 -$...0dB 20 * log
(inCalibrate/
32768)
outBbcGain EPP/EPN analog output gain of
baseband controller after DAC
0...3 0...-18dB 6dB steps
outCalibrate[n]
n = 0...4
digital attenuation of output signal
after speech decoder, before
summation of sidetone and DAC
present for each volume step[n]
0...32767 -$...+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.