SIM5218E Hardware Design
SIM5218E_HD_V1.03
11.06.2009
33
Table 12
: Speaker Output
Characteristics
Parameter
Min
Typ
Max
Unit
Quiescent
Current
6.2
mA
Output
power(1KHz)
500
mW
3.8.5 Programming characteristic
3.8.5.1 Setting Audio Parameters by AT Commands
The audio modes 1 to 3 can be temporarily adjusted according to the AT command parameters
listed in the table below. The audio parameters are set with the AT commands AT+CMIC,
AT+SIDET, AT+CTXGAIN, AT+CRXGAIN, AT+CTXVOL, AT+CTXFTR, AT+CRXFTR as
well as AT+VGR, AT+VMUTE, AT+MICMUT, AT+CSDVC, AT+CPTONE. For a model of how
the parameters influence the audio signal path see Section 3.8.5.2.
Table 13: Audio parameters adjustable by AT command
Parameter
Influence to
Range
Gain
range
Calculation
AT command
micAmp1
MICP/MICN analogue
amplifier gain of before
ADC
0…1
0…24dB
2 steps
AT+CMICAMP1
micAmp
MICP/MICN analogue
amplifier gain of before
ADC
0…15
0…22.5d
B
1.5 dB steps AT+CMIC
txVol
Digital gain of input signal
after ADC
0,
1...65535
Mute,
-84...+12
dB
20 * log
(txVol/
16384)
AT+CTXVOL
txGain
Digital gain of input signal
after summation of
sidetone
0,
1...65535
Mute,
-84...+12
dB
20 * log
(txGain/
16384)
AT+CTXGAIN
txFilter
Input PCM 13-tap filter
parameters, 7 values
0...65535
---
MATLAB
calculate
AT+CTXFTR
rxGain
Digital gain of output
signal after summation of
sidetone
0,
1...65535
Mute,
-84...+12
dB
20 * log
(rxGain/
16384)
AT+CRXGAIN
rxVol
Digital Volume of output
signal after speech
decoder, before summation
of sidetone and DAC
-300…300
dbm
-300…300db
m
AT+CRXVOL
