Silicon Laboratories SI2494/39, SI2493/57/34/15/04 manual Speakerphone Configuration

AN93

7.7.4. Speakerphone Configuration

This section covers the speakerphone call and answer cases, and the switching between the handset mode and speakerphone mode. Table 136 contains the initial configuration that is used by all dialing use cases. The sequence is also sent for the answer case. The user will have been notified of the incoming call through a local +VTS ring tone and a SP Button On Event would prompt the Speakerphone Configuration sequence to answer the call. The UB1, UB5, UB6, and Si3000 register configurations vary with the customer’s production hardware. The UB5 register serves as the general volume control in this mode.

Table 136. Speakerphone Configuration

Host to Modem Commands / Data	Modem to Host	Local Modem Actions
	Result Codes/
	Data
AT:U199A	OK	Mute the microphone and speaker paths to
		the codec.
AT+VLS=0	OK	Disable voice mode. Used as a transition
		point between non-zero +VLS voice modes.
		Setup off-hook voice mode. See Table 117
AT+VLS=13	OK	on page 190 for details. This command will
		switch the modem to off-hook state.
AT:U0B1,0500	OK	Restore Si3000-to-DAA transmit gain path.
AT:U0B5,0200	OK	Restore DAA-to-Si3000 receive gain path.
		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:
		10 dB Line In gain
		Enable Line In
AT:U72,0597	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

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