12
low logic level to inform the master (client PC). It will stay low until the master
clears the interrupt event with AT command.
If Full Modem is used to establish communication between devices, the pin “RI” is
another operation status. Initially it keeps high, when a voice call or CSD call comes,
the pin “RI” will change to low for about 5900ms, then it will return to high level for
100ms. It will repeat this procedure until this call is answered or hung up.
Note: RC3000A supports the communication rate: 300, 600, 1200, 2400, 4800, 9600,
19200, 38400, 57600, 115200, 230400, 460800, 921600, 3200000, 3686400,
4000000bps. Default rate is 115200bps.
B.
Audio Interface:
RC3000A-E provides two analog signal outputs and one analog input. MIC1P/N is
used as microphone, EAR1P/N and SPK_P/N are used as audio output. Regarding
audio parameters configuration, please refer to the ATC manual.
There are three audio channels in RC3000A, including speaker output, receiver
output and microphone input. SPEAKER circuit in RC3000A is a Class-D amplifier.
Note: RC3000A has integrated MIC bias circuit. There is no need to pull the MIC1P
and MIC1N up to the external power, just connect it to microphone. MIC1P and
MIC1N must be differential lines.
Main audio parameters can be changed to satisfy users’ requirement. Here primary
register parameters and related description are listed. User can adjust them through
AT command.
Audio Parameter:
Parameter
Influence
to
Range
Gain range
Calculation
AT command
micAmp1
MICP/MICN
analogue
amplifier
gain before
ADC
0…1
0…24dB
2 steps
AT+CMICAMP1
txVol
Digital gain
of input
signal after
ADC
0,
1…65535
Mute,
-84…+12dB
20 * log
(txVol/16384)
AT+CTXVOL
txGain
Digital gain
of input
signal after
summation
of sidetone
0,
1…65535
Mute,
-84…+12dB
20 * log
(txGain/16384)
AT+CTXGAIN