AN93

7.5.8. Speakerphone Transition

In the Handset mode, the SP Button On Event will trigger the transition from Handset to Speakerphone mode. See "7.7. Speakerphone" on page 212 for details on Speakerphone mode. The voice driver should track the handset hook switch state, such that if the user exits Speakerphone mode, the system will switch back to Handset configuration without losing the active call.

Table 125. Handset to Speakerphone Transition

Host to Modem

Modem to Host Result

Local Modem Actions

Commands / Data

Codes/Data

 

 

 

 

AT:U199A

OK

Mute the microphone and speaker paths to the codec.

 

 

 

 

 

Configure Si3000 Register 1:

 

 

Disable speaker driver

AT:U72,0108

OK

Enable line output driver

 

 

Disable telephone instrument driver

 

 

Disable MBIAS output

 

 

 

 

 

Configure Si3000 Register 5:

 

 

20 dB Line In gain

 

 

Enable Line In

AT:U72,05D7

OK

20 dB MIC input gain

 

 

Mute MIC input

 

 

Mute telephone instrument input

 

 

Enable IIR filter

 

 

 

 

 

Configure Si3000 Register 6:

AT:U72,065E

OK

0 dB RX PGA gain

Enable Line Out

 

 

 

 

Disable telephone instrument output

 

 

 

 

 

Configure Si3000 Register 7:

AT:U72,075E

OK

0 dB RX PGA gain

Enable SPKRL

 

 

 

 

Mute SPKRR

 

 

 

 

 

Configure Si3000 Register 9:

AT:U72,0900

OK

0 dB Line Out attenuation

 

 

0 dB Speaker output attenuation

 

 

 

AT+VSP=1

OK

Enable speakerphone voice path. See Figure 29 on

page 188 for details.

 

 

 

 

 

AT:U199&FFF5

OK

Enable the microphone and speaker paths to the codec.

 

 

 

200

Rev. 1.3

Page 200
Image 200
Silicon Laboratories SI2493/57/34/15/04, SI2494/39 manual Handset to Speakerphone Transition, AT+VSP=1