Silicon Laboratories SI2494/39, SI2493/57/34/15/04 manual AT+VLS=0, AT+VLS=13, AT+VSP=0

		AN93
Table 120. Handset Configuration
	Modem to Host
Host to Modem Commands / Data	Result Codes/	Local Modem Actions
	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.
AT+VLS=13	OK	Setup off-hook voice mode. See Table 117
		on page 190 for details.
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:
	OK	Enable speaker driver
AT:U72,0110		Disable line output driver
		Disable telephone instrument driver
		Enable MBIAS output
		Configure Si3000 Register 5:
		10 dB Line In gain
	OK	Mute Line In
AT:U72,05B3		20 dB MIC input gain
		Enable MIC input
		Mute telephone instrument input
		Enable IIR filter
		Configure Si3000 Register 6:
AT:U72,065C	OK	0 dB RX PGA gain
		Disable Line Out
		Disable telephone instrument output
		Configure Si3000 Register 7:
AT:U72,075E	OK	0 dB RX PGA gain
		Enable SPKRL
		Mute SPKRR
	OK	Configure Si3000 Register 9:
AT:U72,0900		0 dB Line Out attenuation
		0 dB Speaker output attenuation
AT+VSP=0	OK	Select handset voice path. See Figure 29 on
		page 188 for details.
AT:U199&FFF5	OK	Enable the microphone and speaker paths
		to the codec.

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