User's Manual
Table Of Contents
- Document history
- Introduction
- Product concept
- Application Interface
- Antenna interface
- Electrical, reliability and radio characteristics
- Mechanics
- Reference Approval
- Design example
- List of parts and accessories
MC55/56 Hardware Interface Description
Confidential / Preliminary
s
MC55/56_hd_v03.00 Page 85 of 104 16.08.2005
5.5 Electrical characteristics of the voiceband part
5.5.1 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 28: 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.