Silicon Laboratories SI2493/57/34/15/04, SI2494/39 manual Voice Compression Method, Signed PCM

Models: SI2493/57/34/15/04 SI2494/39

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AN93

 

Table 39. Basic AT Command Set (Continued)

 

 

 

 

Command

 

 

Action

 

 

 

+VSM = n

 

Voice Compression Method.

 

 

0 Signed PCM

 

 

 

1 Unsigned PCM

 

 

4 G.711 µ-Law

 

 

 

5 G.711 A-Law

 

 

 

129 ADPCM 2-bit (2 kB/s storage)

 

 

131 ADPCM 4-bit (4 kB/s storage)

 

 

 

+VSP

 

Voice Speakerphone State

 

 

<mode> Description

 

 

0 Speakerphone AEC, AES and LEC disabled.

 

 

Handset FIR filter coefficients are selected.

 

 

1 Speakerphone AEC, AES and LEC enabled.

 

 

Speakerphone FIR filter coefficients are selected.

 

 

The +VLS=13 command must be used in combination with this

 

 

setting.

 

 

 

 

+VTD = n

 

DTMF / Tone Duration Timer.

 

 

This command sets the default DTMF / tone generation duration in

 

 

10 ms units for the +VTS command. Default time is 1 second

 

 

(n = 100).

 

 

 

 

+VTS = [<freq

 

DTMF and Tone Generation.

1>, <freq2>,

 

This command can be used to produce DTMF tones, single-fre-

<dur>]

 

quency tones, and double-frequency tones. Note that the bracket

 

 

characters are required for correct operation.

 

 

<freq1>

Frequency one, which has a range of 0, 200-

 

 

3200 Hz.

 

 

 

<freq2>

Frequency two, which has a range of 0, 200-

 

 

3200 Hz.

 

 

 

<dur>

Duration of the tone(s) in 10 ms units.

 

 

 

+VTX

 

Transmit Voice Samples.

 

 

Used for sending digitized voice samples from host memory

 

 

through the UART interface. The +VSM command determines the

 

 

format of the samples. Multiple routing options are available.

 

 

 

 

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Rev. 1.3

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Silicon Laboratories SI2493/57/34/15/04, SI2494/39 manual Voice Compression Method, Signed PCM, Voice Speakerphone State