Specifications

Chapter 16 – Audio Commands
Multi-Tech Systems, Inc. AT Commands for EDGE (E1) Modems (S000474A) 264
• The parameters <clock>, <mode> and <frame_mode> are mandatory, if parameter <io> is set to 1 (digital).
These parameters can be used to configure the PCM functionality over the digital audio interface (DAI). The
PCM interface supports master or slave mode, short frame or long frame synchronization and 256 kHz or 512
kHz bit clock frequency. In slave mode the clock frequency setting has no influence, because of the BCLKIN
signal being directly used for data shifting. The setting may therefore be either 0 or 1. The table below lists
possible configuration combinations.
Configuration <clock> <mode> <framemode>
Master, 256kHz, short frame 0 0 0
Master, 256kHz, long frame 0 0 1
Master, 512kHz, short frame 1 0 0
Master, 512kHz, long frame 1 0 1
Slave, 256kHz, short frame 0 or 1 1 0
Slave, 256kHz, long frame 0 or 1 1 1
Slave, 512kHz, short frame 0 or 1 1 0
Slave, 512kHz, long frame 0 or 1 1 1
• This command is not PIN protected.
• This command is supported in airplane mode.
16.9 AT^SNFA Set or Query Microphone Attenuation
Description: AT^SNFA specifies the large-scale attenuation on the microphone path of the audio device
currently selected with AT^SNFS. The write command is only available in audio modes 2 to 6.
Syntax: Test Command: AT^SNFA=?
Response: ^SNFA: (list of supported <atten>s)
OK
Read Command: AT^SNFA?
Response: ^SNFA: <atten>
OK
ERROR
+CME ERROR: <err>
Write Command: AT^SNFA=<atten>
Response: OK
ERROR
+CME ERROR: <err>
Parameter:
<atten>
Multiplication factor for input samples. Parameter <atten> is identical with <inCalibrate> of AT^SNFI.
Formula used to calculate microphone attenuation (negative gain):
Gain in dB = 20 * log(<atten>/32768)
0.....65535
0 Microphone is muted.
Please note that AT^SNFA cannot be used to mute the microphone. Therefore, any attempt to
enter 0 will be rejected and an error response will be given. Value 0 is returned only by the read
command AT^SNFA? after the microphone was muted with AT^SNFM=0 during an active call.
32767 Default=32767. This is a powerup default which is not stored at power down. No attenuation on
the microphone path. Values greater than 32767 will be suppressed to 32767.
Example:
^SYSSTART
at^snfa=?
^SNFA: (0-65535)
OK
at^snfa?
^SNFA: 32767
OK
at^snfs=4
OK
at^snfa=1
OK
at^snfa?
^SNFA: 1
OK
at^snfi?
^SNFI: 5,1
Example continues on next page.